330 The Unity of the Organism 



between the corresponding stages in the life of each individ- 

 ual, and undoubtedly between an individual and its progeny, 

 they are an instance of heredity ; and since their development 

 is directly contributed to by the chromatic body of the 

 nucleus, we have here a clear instance of chromatin acting 

 as a mechanism of heredity. 



The reader will recall that in Crithidia leptocoridis and 

 in Giardia muris, two protozoans quite different from each 

 other and both very different from the amoeba-like creature 

 just described, the flagella of the adults are also connected, 

 by way of a blepharoplast, with the central chromatic body 

 of the nucleus. The same connection is known to occur in 

 numerous other protozoans. Indeed, its occurrence is so 

 frequent that some authorities now regard flagella in gen- 

 eral as belonging to the nuclear system. Minchin particu- 

 larly is a supporter of this view. Starting from species like 

 Mastigwa setosa in which Goldschmidt has shown that the 

 flagellum seems to arise directly from the nucleus, Minchin 

 presents a scheme of "possible phylogenetic origin of the 

 different types of flagellar attachment in flagellates." 



An important element in the general problem of the rela- 

 tion of flagella and cilia to nuclei is the question of the 

 origin and nature of the blepharoplast. The statement was 

 made when we were examining the adult anatomy of Giardia 

 muris that the blepharoplast question would receive further 

 consideration in the discussion now occupying us. This 

 question is fundamentally connected with a cell organ which, 

 though of undoubtedly high importance, has not hitherto 

 figured in our treatment. Reference is made to the ccntro- 

 some. 



X 



The term "blepharoplast" (from the Greek blepharon, eyelash) 

 came into biology from the botanical side. It was applied by 

 Webber to a body occurring in the spermatogenous cells of 

 (iinkiro and /tun ia, "because of their special function as cilia- 

 formers/' the spermatozoids being derived from the body in 



