174 Fertilisation 



organs. After fertilization they multiply by division, and 

 thus form the chromatophores of the new individual. In 

 regard to this point the organization of the protoplasts 

 is therefore inherited directly from the mother and not 

 from the father. 



Let us now see, how the other members of the proto- 

 plast, with the exception of the nucleus, behave. To all 

 appearances the spermatozoids possess neither vacuoles 

 nor chromatic bodies, and hence the condition is the same 

 for the former as for the latter. 



According to the best recent investigations, the sper- 

 matozoids do not originate, as some authors previously 

 assumed, from the nucleus only of the mother-cell, but 

 the rest of the plasma also takes part in their formation. 

 It is true that the nucleus forms the bulk of the body of 

 the male reproductive cell. Schacht has already voiced 

 the theory, on the basis of his observations and those of 

 others, ''that the nucleus takes a very active part in the for- 

 mation of the spermatozoid and in a certain way blends 

 into it."" He declares further that, in this process, the 

 granular contents of the mother-cell disappear. This trans- 

 formation of the nucleus, although denied by prominent 

 investigators^^ at the beginning of the more recent re- 

 searches, is now generally recognized as the most im- 

 portant part of the whole process. 



Outside the nucleus there lies, in the spermatozoids, 

 the limiting membrane, which protects this organ against 

 external influences, and, in a certain way, serves as the 

 little boat that carries it to its destination. The distinc- 



11 Schacht. Die Spermatozoiden p. 35. 1864. 



i^Comp. e. g. Sachs, Lehrbuch, 4. Auflage, p. 303; and Stras- 

 burger, Zellhildung und Zelltheilung, III Aufl. p. 94; also Bot. Zeit. 

 39: 847, 848. 1881. 



