138 On the Genetics of the Cilia te Protozoa 



here, moreover, beeause the ciinjiigants as well as their gamete nuclei 

 fuse during conjugation, so that only one complex zygote results. It 

 seems to me necessary to lay special emphasis on the preceding state- 

 ments, because the terms " gamete," " sex," " male " and " female " are 

 almost always misused in the case of the ciliates, and a very great deal 

 of confusion has arisen in consequence'. It is manifest that " male 

 sex " or " female sex " is properly predicated of individuals, which are 

 ultimately known by the gametes which they produce. To suppose 

 that a " male gamete " is itself a male is absurd. This misleading term 

 really signifies " a gamete produced by a male individual." The gamete 

 itself has no sex — within the legitimate meaning of the word. 



15. Lastly, it should be clearly realized that among the ciliates the 

 sole method of reproduction is by division. Sexual "reproduction" (in 

 the sense of " multiplication ") does not occur". The zygote is a con- 

 jugant reorganized — a new individual raised upon the ruins of an old, 

 without any increase in the number of individuals. After conjugation, 

 the exconjugant reproduces by fission (the earliest divisions being 

 sometimes modified, cf. § 5) in essentially the same manner as any 

 other individual. All " genei'ations " are produced asexually — by fission 

 or budding. The only " sexually produced generation " is the excon- 

 jugant, which is merely the conjugant reorganized — an individual 

 thrown into the melting pot, with a bit of another individual, and 

 recast. In the case of the Vorticellids (§ 6), two whole individuals, 

 as well as their gametes, fuse to form one zygote ; so that sexual 

 " reproduction " in these forms results in a reduction — not increase — 

 in the number of individuals. 



To convince himself of this, the reader need only refer to almost any of the recent 

 works dealing with genetic experiments on ciliates. He will find that the same author 

 assumes a conjugant to be a cell, a gamete, or a sexual organism, at pleasure — according 

 to the requirements of the argument. Examples of such inconsistencies could be given 

 by the dozen. 



- "Ce n'est pas, en effet, un des resultats les moins surprenants des recherches sur 

 la f^condation des Cilifa, de voir que son Evolution et ses manifestations si complexes 

 n'aboutissent a la multiplication on a la reproduction d'aucuu etre nouveau " (Maupas, 

 1889, p. 435). 



