816 4. Fortpflanzungslehre. 



surface libre. La cellule parietale dont le noyau est en chromatolyse demeure 

 dans la muqueuse oü eile est phagocytee par des mononucleaires. 



Aux Stades plus jeunes le contenu du kyste est forme d'uu plasmode ä 

 tres nombreux noyaux isoles ou ranges en nombre quelconque, en masses 

 morulaires (blastopbores) qui s'individualisent et se separent par resorption du 

 cytoplasme interstitiel. Dans ces blastopbores tous les noyaux sont ranges ä 

 la peripherie. Chacun d'eux devient le noyau d'un germe qui est bourgeonne 

 par le blastophore. Ces gerraes ranges autour de leur reliquat central rappel- 

 lent les gymnospores de la Porospora du Homard. Ils se separent avant 

 leur expulsives. 



La question des affinites de cet organisme est subordonnee ä la nature 

 de la cellule parietale. L'auteur incline ä penser que celle-ci est une cellule 

 böte hypertrophiee par l'action du parasite, action qui aurait provoque aussi la 

 formation du revetement en brosse peripherique, comrae c'est le cas pour 

 les lymphocytes des oligochetes parasites par les Microsporidies du genre 

 Myxocystis (Mrazek). 



Le parasite de Gilruth, Gastrocystis gilruthi, paraft etroitement 

 apparente aux sporozoaires sensu-stricto: Coccidies-Gregarines. Des recherches 

 recentes incitent l'auteur ä penser qu'il n'a rien de commun avec les sarco- 

 sporidies. E. Chatton (Paris). 



1769) Robertson, M. (Lister Institute London), Studies on Ceylon 

 Haematozoa. II. Notes on the Life-cycle of Haemogregarina 

 nicoriae. 



(Quart. Journ. Micr. Science 55,4. p. 741—759. 10 plates. 1910.) 

 Haemogregarina nicoriae is found in the blood of the tortoise 

 Nicoria in Ceylon. It occurs in two types, bean-shaped and recurved. Certain 

 of the bean-shaped forms give rise by schizogony in the lungs to about seventy 

 merozoites. Other bean-shaped individuals give rise in the circulating corpus- 

 cles to a small number (6 — 8) of quite small merozoites. The form which 

 undergoes this second type of schizogony is probably derived from the mero- 

 zoites produced in the lung. The small merozoites probably give rise to 

 gametocytes, the schizogony in the lung being endogenous asexual multiplication. 

 When the haemogregarines are swallowed with blood by the leech Ozo- 

 branchus, certain of them pass into the intestine and become motile vermi- 

 cules. They penetrate the intestinal wall, where the gametes are differen- 

 tiated, and it appears that anisogamous conjugation takes place. The zygote 

 breaks up into eight sporozoites, which pass into the blood of the leech. 

 Reinfection of the tortoise is probably by the bite of the leech. 



Doncaster (Cambridge). 



1770) Pearl, R. and F. R. Surface, Experiments in Breeding Sweet 

 Corn. 



(Ann. Rept. Me. Agric. Expt. Stat. p. 249—307. 8 plates. 1910.) 

 This paper deals with experiments extending over a period of three years 

 and having as their object the improvement by selection of two types of the 

 sweet variety of maize (Zea mays saccharata). The primary objects in the 

 selection were to improve the maize in respect to earliness of maturity, yield, 

 and conformation of ear. A marked gain earliness was observed after the 

 first years selection. This gain was maintained in subsequent years but no 

 further gain in respect to this character has been made by continued selection. 

 All the improvement in this respect that was accomplished was made by the 

 first years selection. A similar improvement in respect to the conformation 

 of the ear followed the first years selection and has been maintained but not 



