251 



reminded of what most of these are due to, i. e. to the differentiation 

 of the conjugating individuals into macro -zooids and micro - zooids. 

 The terms macro- and micro-gametes used by Maupas are misnomers, 

 for, as other instances have made evident, the individuals which are 

 present at the beginning of the union culminating in conjugation are 

 not really the conjugating forms. The true gametes are formed later 

 on within, and as descendants of, the "micro"- and "macro-gamete". 



Fig. 5. 



6. 7. 



Macro2oaid 



Microzooict 



The differentiation into these can hardly be said to affect the con- 

 jugating gametes; the latter are alike, as in other cases, and do not 

 differ in form, as Maupas has shown. It would be incorrect to term 

 the "micro"- and "macro-gametes" male and female respectively. This 

 is something which should be reserved for the terminology of Meta- 

 zoau individuals, where the gametes differ in form, although they are, 

 as demonstrated by Bovery and 0. Hertwig, morphologically equi- 

 valent. In other words we are not entitled to speak of sex in the 

 Infusoria hitherto investigated. 



Before venturing on an interpretatation of the whole process in 

 Vorticella, I should like to pay a tribute of admiration to Mau- 

 pas' brilliant researches. They stand out prominently among the 

 published results of recent years as marvels of patience, exactitude, 

 and morphological insight. It is a somewhat painful position to find 



