538 ANNALES DE L'INSTITLT PASTEUR 



tozoa which wcnl to press early in 1912 and was published in 

 September of that year. In that work I wrole (p. 306) : — 

 (( That a trypanosome or any other living cell might excrete 

 o-rains which, when set free, could exhibit movements due to 

 moL'Cular or other causes, is highly probable; but that such 

 «i-rains represent a stage in the life-history of a trypanosome is 

 far from being so. » At I he time I wrote these words the only 

 fio'ure of the « infeclive granules » that had been published, so 

 far as I am aware, was the diagrammatic and scarcely convin- 

 cino' figure given by Fry, and in my criticism I was misled by 

 assuming that the word « granule » was used by Balfour and 

 Fry in the ordinary cytological sense of the word. Subse- 

 quently the formation of « infective granules » in Hœmogre- 

 garines was described in detail by Dr. Herbert Henry in 1913, 

 and in the same year a full account of these bodies was 

 published by Fry and Ranken. Both these memoirs were 

 accompanied by numerous illustrations, from which (and spe- 

 cially fi'om these given by Fry and Ranken) it seems to me 

 quite cb^ar that the term « granule » applied lo these bodies is 

 a complete misnomer; they are not cell-granules in the oi'di- 

 nary sense of the term, but endogenous buds, the formation 

 of which begins by a concentration of chromidia, and each 

 bud, when complete, has the morphological and cytological 

 value of a true cell, very minute in size and reduced almost 

 entirely to its chromatin-elements; the cytoplasm so small in 

 amount as to be practically invisible, or perhaps absent 

 altogether. 



In order to establish this interpretation, I may first draw 

 attention to the many known examples of endogenous budding 

 in other Protozoa, and specially in the Amœba^a. There are, 

 in fact, so many exam|)les of this process of reproduction 

 known to occur in Amocbaea that in a short note it is impos- 

 sible to refer to them all; I must content myself here by men- 

 tioning a few typical instances, such as the life-history of 

 ArceHa (summarized in my book, pp. 177-181 and fig. <S0) and 

 that of Amœba minuta, recently published by Popoff, and I will 

 deal presently in more detail with the very typical instance 

 described by Liston and Martin. In Flagellata, instances of this 

 method of i-eproduction are less common, but typical examples 



