REPROD UCTION 



55 



producing, first, two with four nuclei {p) and, 'then, four small 

 individuals, each containing a macronucleus and a micronucleus 



Anisogamous conjugation is essentially the same except that 

 the conjugants are dissimilar in size and in some cases in struc- 

 ture. In Chilodon (Fig. 27), the conjugants are unequal in size. 

 According to Dogiel, in Cycloposthium hipalmatum (Fig. 27) 



Fig. 27 



a. Anisogamous conjugation in Chilodon cucullulus. X140. (After 

 Engelmann). b. Anisogamous conjugation in Cycloposthium bipal- 

 matum. X245 (After Dogiel). 



conjugation takes place between two similar individuals or 

 between two unequal ones. 



A sexual process which is somewhat intermediate between 

 copulation and conjugation is noted in certain ciliates. Accord- 

 ing to Maupas' classical work on Vorticella nehulifera, the 

 ordinary trophic individual divides twice, forming four small in- 

 dividuals, which become detached from one another and swim 

 about independently. Sooner or later each of these small or- 

 ganisms attaches itself to one side of an ordinary stalked in- 

 dividual. In it the micronucleus divides three times and 



