222 8- Abstammungslehre. 



aus den Mendelschen Gesetzen „entweder Knospenvariationen oder Aktivwerden 

 latenter Erbeinheiten im Mendelschen Sinne" sind. Hilz heim er (Stuttgart). 



408) Petrunkevitch, A., Relation between Species and Individual 

 in the Struggle for Existence. 



(The New York Academy of Sciences Section of Biology. 14. März 1910.) 

 From examples taken from the groups of spiders and insects the Speaker 

 tried to show that the advantage of the individual is often opposed to the 

 advantage of the species. Structures and habits dangerous to the individual 

 but of use to the species are not uncommon. Their existence proves that the 

 individual is „enslaved" by the species, which condition may be understood 

 only if we consider the individual a mere carrier and protector of the germ. 

 In the evolution of species not the cbaracters of the fittcst individual are 

 selected and transmitted to the descendant, but those of the fittest to preserve 

 the progeny. Hussakof (Newyork). 



409) Wood, Miss. Elvira, A Case of Apparent Reversion among 

 Gastropods. 



(The New York Academy of Science Section of Biology. 14. März 1910.) 



The Ornament of Potamidopsis tricarinatum begins as two continuous 

 spirals, passes through a stage with two rows of nodes and interpolates a 

 third row of nodes in the adult. Potamidopsis trochleare has three rows of 

 nodes in the young, later loses the median row and has in the adult two 

 continuous spirals. This suggests reversion in the latter species, but in 

 P. tricarinatum the upper spiral disappears before the introduction of the 

 subsutural and median rows of nodes, while in P. trochleare the upper conti- 

 nuous spiral of the adult is developed from the subsutural nodes, hence the 

 two spirals of the adult are not equivalent to the two spirals of the young 

 P. tricarinatum. P. trochleare illustrates progressive development resulting in 

 simplification of structures. Hussakof (Newyork). 



410) Cole, Leon J. (University of Wiscosill), Über eigenartige lokale 

 Bedingungen in der Lebensweise eines zum erstenmal in Nord- 

 amerika gefundenen Pycnogoniden (Endeis spinosus). Mit Be- 

 merkungen über das Herz und die Zirkulation bei demselben. 



(Biological Bulletin 18,4. p. 193—203. März 1910.) 

 Cole bestimmt einen zwischen Kolonien von Obelia dichotoma, die auf 

 Sargassum bei Woods Hole wuchsen, gefundenen Pyknogoniden als Endeis spi- 

 nosus (Montagu). Diese pelagische Lebensweise steht unter den Pyknogoniden 

 einzig da. Beim Schwimmen bewegen sich die Individuen gleichmäßig einer 

 mäßig intensiven Lichtquelle zu. Der Verf. beschreibt Herz und Blutumlauf. 

 Das Herz schlägt etwa 172 mal per Minute. Frank Lillie (Chicago). 



Berichtigung. 



Im Referat Nr. 76 (H. 1. p. 52) Z. 8: statt „Degenerationsmitosen" zu lesen 

 „Degenerationsamitosen". Gutherz (Berlin). 



Alle Zusendungen sind zu richten an Prof. Dr. Poll, Berlin NW 40, Hindersinstr. 3. Alle geschäft- 

 lichen Mitteilungen (Reklamationen, Zahlungen usw.) wolle man richten an S. Hirzel, Leipzig, König- 

 straße 2. Verantwortlicher Redakteur Prof. Dr. Poll. — Druck von August Pries in Leipzig. 



