ALBERT

Beschreibung: A biometrical analysis of preserved specimens of Bufo bufo, supplemented by a detailed examination of the shape of the skin warts, was performed in order to ascertain the taxonomic status of the form described as B.b.spinosus. Indications of a N.-S. clinal variation in the formation of wart thorns and in allometric relations of body elements were found. The validity of the form as a distinct subspecies seems accordingly very doubtful.

Beschreibung: Dr. Ernst Frederik Jacobi, who was a member of the Editorial Board of this journal for exactly 20 years, reached the age of 65 on September 11, 1973 and retired.\nDr. Jacobi was appointed Director of the Amsterdam Zoo (officially: of the Royal Zoological Society \xe2\x80\x9cNatura Artis Magistra\xe2\x80\x9d) on April 1, 1953, in succession to Dr. A. L. J. Sunier. The function of Director of the Zoo automatically means also the membership of the Editorial Board of \xe2\x80\x9cBijdragen tot de Dierkunde\xe2\x80\x9d. This periodical was published by the Royal Zoological Society until vol. 28 of 1949 (the last volume edited by Dr. Jacobi\xe2\x80\x99s predecessor), but owing to the difficult financial situation of the Society, its publication was interrupted from 1949 to 1959, when vol. 29 appeared. From this volume onward, the \xe2\x80\x9cBijdragen\xe2\x80\x9d appeared at regular periods, first once a year, later twice a year; also, the periodical was no longer published by the Royal Zoological Society solely, but by a committee (called so beautifully the \xe2\x80\x9cBoard of Supervisors on the Management of the Artis Library\xe2\x80\x9d, the Artis Library being the library of the Society, though since 1938 chiefly managed by the University of Amsterdam).

Beschreibung: Positive identification of bats usually requires visual inspection at close range or for a bat to be held in the hand. There are many people, particularly conservationists, who would like to study bats in their natural environment without disturbing them.\nThe task of preparing distribution maps is at present a slow and painstaking task, depending on the limited number of observers who can accurately identify bats. Most bats emerge at dusk and although some can be seen in such poor lighting conditions, most bats flying at night cannot be observed when below the horizon and against a dark background.

Beschreibung: A biography of H. E. van Rijgersma is given, with the genealogical register of his family. The zoological and historical literature, in which he was mentioned, is discussed. Van Rijgersma\'s illustrated manuscripts on botany (1868) and malacology (1875) of St. Martin, and his correspondence with malacologists, were discovered in the United States and studied. The recent mollusk fauna of St. Martin is summarized, consisting of 550 species, of which 136 are new to the fauna of that island.

Beschreibung: Under the chairmanship of dr. A. van Wijngaarden (Netherlands\xe2\x80\x99 Institute of Nature Research) a discussion on bat conservation was held. Seventeen speakers, representing 13 countries reported on the problems existing in various areas. Reports came from Van Wijngaarden and Braaksma (the Netherlands), Racey and Stebbings (United Kingdom), Gaisler (Czechoslovakia), Issel (Germany), Jensen (Denmark), Rydberg (Sweden, comments on the situation in Finland), Stock (situation in Belgium), Saint Girons (France), Dinale (Italy), Duli\xc4\x87 (Yugoslavia), Mutere (Kenya), Lendell Cockrum, Myers, Koopman (U.S.A.), Greenhall (Mexico).\nSummarizing, it turned out that urbanisation, the use of insecticides in agricultural areas and in summer roosts, large scale banding of bats by nonqualified people, amateur-speleology, and irresponsible bat control connected with the rabies and vampire problem, are the main causes of decrease in bat populations.

Beschreibung: Some data on the distribution in Norway and on the ecology of the euryhaline amphipods Gammarus duebeni duebeni, G. oceanicus, G. zaddachi, G. finmarchicus and Chaetogammarus marinus are presented in this paper.\nMorphological differences between populations of G. oceanicus are briefly discussed.

Beschreibung: 1. The migration of two sympatric estuarine species has been studied over a period of one year in the estuary of the river Dourduff, a small river draining into the Bay of Morlaix (Brittany, France). One species, Gammarus zaddachi, is a boreal species and the other, Gammarus chevreuxi, is a lusitanian species. Both species live near the limits of their distribution area. 2. Both species show a migration pattern with an anadromous and a catadromous phase. The migration is an active process. The animals use the tidal movements for their upstream and downstream migration. 3. Migration activities of both species show a diurnal rhythm, the activity peak occurring at night. 4. Downriver migration of both species can be observed throughout the whole year. Upstream migration, however, only takes place during periods with high water spring tide. During these periods the stream reverses direction and water with higher salinities enters the limnic parts of the river. 5. Per night the maximum numbers of anadromous and catadromous migrating individuals caught in a net of 30 X 50 cm were 30,000 and 800,000 respectively for G. chevreuxi. For G. zaddachi these numbers are considerably lower. 6. In both species the composition of the samples from upstream and downstream catches were different. In general, upstream migrating animals are smaller and younger than downstream migrating individuals. 7. G. zaddachi invades the limnic reaches of the river only when water temperatures drop below 6\xe2\x80\x948\xc2\xb0 C, a situation occurring for a period of only a few weeks. 8. G. zaddachi reproduces only during the winter months when water temperatures are relatively low. Reproduction takes place in areas with constant or at least periodical influence of mixohaline waters. In the limnic reaches of the Dourduff reproduction is never observed. 9. G. chevreuxi migrates farther upstream than G. zaddachi. It can stay in completely fresh water for more than four months. 10. G. chevreuxi can reproduce during the whole year. Reproduction has never been observed in completely fresh areas, although downstream migrating ovigerous females can be found. 11. In a series of laboratory experiments, survival rates and reproduction capacity were determined under various different temperature/salinity conditions. 12. Temperature has a strong influence on the salinity tolerance of G. zaddachi. At 5\xc2\xb0 C the mortality rate in river water is comparable to that under optimal salinity conditions. At higher temperatures the mortality sharply increases at lower salinities. 13. Increasing salinity as well as decreasing temperatures have a positive influence upon the reproduction rate of G. zaddachi. In rearing experiments no reproduction has been observed in limnic (= natural) water of the Dourduff, at 5\xc2\xb0 C. 14. For G. chevreuxi the situation is different. At 5\xc2\xb0 C survival is low at all salinities. Under brackish conditions (0.8\xe2\x80\xb0 and 8.0\xe2\x80\xb0 Cl) a rise in temperature results in a higher survival rate. In fresh water however (0.08\xe2\x80\xb0 Cl), rise of temperature causes a higher mortality rate. 15. In rearing experiments G. chevreuxi does not reproduce in completely fresh water. Under mixohaline conditions reproduction has been observed at all temperatures examined. 16. The reproduction cycle of the two species is shown in diagrammatic models.

Beschreibung: Description of Echinogammarus spinulicornis nov. spec., closely related to E. pungens (H. Milne Edwards), and of Echinogammarus zebrinus nov. spec., a member of the E. berilloni-group, from streams in the Basin of Aquitaine, southwestern France.

Beschreibung: Czechoslovakia, fortunately enough, belongs to the regions having still numerous habitats resembling the original ones, or at least suitable to the needs of many original species of mammals. This concerns especially the bats while these animals are partly adapted to a synanthropic way of life in a country with many old buildings, parks, woods of different types, etc. Therefore, the protection of bats in Czechoslovakia appears not to be such a serious problem as in some other central and western European countries. Apart from the region of the South Slovakian Kars, we have no data on the decline of bat populations as a whole.\nConsidering this, we were interested in the influence of our own activities on the populations in certain localities. This activity concerned banding, recapturing, and also collecting of bats for the purpose of systematic, morphological, parasitological, and physiological investigations. Figs. 1 and 2 show the fluctuations in number of several species of bats recorded in two bat hibernating quarters in Bohemia. Both of these localities are situated in forested areas and populated by such species as Plecotus, Barbastella, and Eptesicus nilssoni \xe2\x80\x94 all of them showing preference for cooler hibernating quarters.

Beschreibung: The horseshoe-bat Rhinolophus ferrumequinum is the best known representative of those bats using constant frequency sounds for echolocation. Schnitzler (1968) has shown, that horseshoe-bats compensate Dopplershifts during flight by lowering the emitted constant frequency so that the heard echofrequency always remains at about 83.4 kHz. His results suggest that horseshoe-bats use the constant frequency part of their orientation sounds for detection and measuring of flight velocities by means of Doppler shifts.\nThe investigation reported here intends to give some clues how constant frequency echoes are processed in the main auditory centre, the colliculus inferior, and how Rhinolophus extracts information for orientation from these echo signals.