404 4. Fortpflanzungslehre. 



der Chromosomenzahl im Gange, sei es im Sinne einer Rückbildung, daß zwei 

 zu einem verschmilzen, oder einer Vermehrung, daß sich ein Element in zwei 

 sondere. Poll (Berlin). 



810) Foot, K. und E. C. Stroheil, Pseudoreduction in the Oogenesis 

 o f A 1 1 o 1 o b o p h o r a f o e t i d a. 



(Arch. f. Zellf. 5,1 p. 149—165. 2 Tafeln. 1910.) 

 Verff. schildern die Ausbildung der Chromosome der ersten Reifeteilungen 

 des Regenwurms, um festzustellen, ob die Kernstadien vor der Wachstumsphase 

 oder nach ihr den Prophasen des Spermatocyten vergleichbar sind. Sie finden 

 nach der Wachstumsphase alle die zum Vergleich nötigen Stadien und stellen 

 sich somit auf Seite Popoffs gegen Gregoire. Für die Frühphasen vor der 

 Wachstumsperiode neigen sie zu Hertwigs Annahme der unterdrückten Kern- 

 teilung. Die Arbeit ist mit wundervollen, zum Teil einzig schönen Mikro- 

 photogrammen illustriert. Goldschmidt (München). 



811) Kirkhaill, W. B. (Yale University), Ovulation in Mammals with 

 Special Reference to the Mouse and the Rat. 



(ßiological Bulletin 18,5. p. 245—251. 1910.) 

 This paper begins with a review of the principal literature on the rela- 

 tion of pairing to Ovulation in mammals, and includes original observations 

 on the mouse and the rat. In both of these animals the author demonstrates 

 that Ovulation occurs entirely independent of pairing. 



1. Four female white mice were isolated and kept apart from all males 

 from the time they were two weeks old. Three were born in the middle of 

 December, 1908, and one early in January, 1909. Of the first three one was 

 killed on March 19, 1909; its ovaries showed fresh corpora lutea and serial 

 sections revealed seven eggs in the Fallopian tubes, all possessing second po- 

 lar spindles. The other two females of this litter were killed March 30, 1909: 

 the Fallopian tubes of one yielded nine eggs similar to the first; the ovaries 

 of the other had white scars indicative of well formed corpora lutea. The 

 female mouse born in January, 1909, was killed March 30, 1909. No trace 

 of either recent or old corpora lutea was seen on the ovaries, and no ova 

 were found in the Fallopian tubes. 



2. In the case of the rats, two females were killed, one 24 hours and 

 the other 48 hours after giving birth to a litter. Characteristic corpora lutea 

 were found on all the ovaries, and serial sections of the Fallopian tubes 

 revealed eight eggs in one animal, five in the other. 



3. The author corrects Ins earlier opinion that, in the case of mouse 

 eggs possessing only one polar body, the first had been extruded through the 

 zona pellucida. He now believes that in such cases the first polar body was 

 disintegrated, thus agreeing with Lams and Doorme. F. Lillie (Chicago.) 



812) Lßger, L. et Duooscq O. (Instituts de Zoologie de Grenoble et Mont- 

 pellier), Etudes sur la sexualite chez les gregarines. 



(Trav. de la Stat. Zool. de Cette. 2ieine s6rie, Memoire 19. p. 19—132. 1910.) 

 Cet important memoire comprend: 



1. Une introduction dans laquelle les auteurs exposent la faQon dont ils 

 comprennent la groupe des Sporozoaires. Ils acccptent le groupe des Telo- 

 sporidies comme comprenant les Coccidies et les Gregarines dont les affinites 

 apparaissent de plus en plus etroites. Mais ils en excluent les Hemosporidies 

 que avcc Schaudinn ils rattachent aux Flagelles, ä cause de l'absence de 



