form two or more grains when there are numerous flagella. Thus, 

 in op&omONa9, which shows the extreme of complication, there are 

 numerous basal granules corresponding to the tuft of flagella 

 (Fig. 45). Each basal granule in this case is divided into a proximal 



Fio. 44. Diagrammatic representation of the possible phylogenetic origin of the 

 different types of flagellar attachment in Hagcllates. For the saUe of sim- 

 plicity it is supposed that the animal lias but a single llagollum. O 1 , Non- 

 tlagellatcd cell with a centriole in the nucleus ; O 1 ', in a cell like the last a 

 flagellum arises from the centriolo ; 1 ;1 , condition with a fiagcllum arising 

 close beside the nucleus ; I 1 ', condition with the blepharoplast quite .separate 

 from the nucleus ; 2 a , division of the single centriole into a definitive centro- 

 some and a blcpharoplast, which becomes quite independent (2 1 ') of the 

 nucleus ; 3*, division of both nucleus and centriole to form distinct kinetic 

 and trophic nuclei, each with its own centriole ; 3 b , the kinetonuclcar centriole 

 remains within the nucleus ; 3 C , the kinetonuclear centriole becomes distinct 

 from the nucleus ; 3 d , condition with a single centriole in the cell ; 3 C , condition 

 with a blepharoplast distinct from the eentrioles of the two nuclei. 



and a distal granule, and the pairs of granules are arranged in a 

 ring, interrupted at one point ; the tuft of flagclla takes origin from 

 the distal granules of the ring. When the nucleus divides, the 

 daughter-centrosomes give rise to new rings of blepharoplasts, 



