Entwicklung, Regeneration, Transplantation. 315 



liaris 2 X csculcntus <S ov acutus <S no vesicles are produced, but one, two, or 

 perhaps soraetimes more chromosomes lag beliind the others in the first segmen- 

 tation division, and are eleminated from the daughter nuclei. 



It is suggested that vesicle-formation may be due either to an alteration 

 of permeability due to the entrance of a Spermatozoon of another species, or to 

 a disturbance of the osmotic relations between chromosomes and cytoplasm, 

 caused by the foreign Spermatozoon giving rise to a pronucleus with different 

 osmotic conditions from those normal to the species. For the relations between 

 the facts here described and the inheritance of Characters in the hybrids, see 

 Shearer, De Morgan and Fuchs, Nr. 1018. Doncaster (Cambridge). 



1018) Shearer, C, De Morgan, W. and Fuchs, H. M., On Paternal Cha- 

 racters in Echinoid Hybrids. In: Quart. Journ. Micr. Sc, Bd. 58, Heft 2, 

 S. 337—352, 2 pl., 1912. 



In a previous paper (Journ. Marine Biol. Soc. IX, p. 121, 1911) the authors 

 gave the results obtained in the years 1909 — 1911 of crossing Ecliinus miliaris 

 with E. acutus and E. csculentus. The characters considered were the posterior 

 «paulettes and posterior pedicellaria (both present in acutus and esculentus, absent 

 in miliaris), and the green pigment masses (present in miliaris, absent in acutus 

 and csculentus). In the years 1909 — 1911, the hybrid larvae, whichever way the 

 cross was made, resembled the female parent in respect of the presence or ab- 

 sence of these characters. In 1912 the crosses were repeated, and when acutus 

 or esculentus was used as female parent the same result as before was obtained. 

 When, however, miliaris was used as female parent in 1912, the result of pre- 

 vious years was reversed; posterior epaulettes were present and green pigment 

 absent. In 1912 the cross-fertilization of miliaris eggs was much less easy than 

 in previous years, and pure miliaris larvae also developed less readily than pre- 

 viously. Further, in one experiment, in which, exceptionally, about 80 per cent, 

 -of the miliaris eggs were fertilized by csculentus sperm, the hybrids were some 

 paternal, others maternal in character. The authors suggest that the difference 

 in behaviour in different years depends on some environmental factor affecting 

 the miliaris female. [Compare Debaisieux, Nr. 1017. Ref.] 



Doncaster (Cambridge). 



Hierzu: Nr. 1027, 1039, 1060—1062, 1065, 1070, 1075, 1078—1080, 1082, 1107, 

 1124, 1125. 



Entwicklung, Eegeneration, Transplantation. 



1019) Yoges, E., Allgemeine Betrachtungen über Regenerationsvor- 

 gänge. In: Biol. Centralbl, Bd. XXXII, Heft 12, S. 697—714, 1912. 



Den Betrachtungen liegen die Vorgänge an den Hagelschlagwunden von 

 Holzgewächsen zugrunde. An der verwundeten Birnfrucht entsteht durch Tei- 

 lung der großen Fruchtfleischzellen ein in seinen Zellelementen radiär angeord- 

 netes Wundkorkgewebe. Die anschließenden Fruchtfleischzellen bilden sich direkt 

 zu Sclerenchymzellen um. In gleicher Weise bilden sich Kork und Sclerenchym- 

 zellen in den Wunden der Zweige aus dem Parenchym und den Markstrahlen 

 des Rindenteiles. Hier treten die Sclerenchymbündel mit den Bastfaserbündeln 

 zu einem geschlossenen mechanischen Bündelring zusammen. Es tritt also ein 

 Organ auf im regenerierten Gewebe, das normalerweise bei den betreffenden 

 Arten nicht vorkommt. Die auffallendste Reaktion auf die Verwundung sind 



