iflG] Swezy: KI)ictiiiiHcl' us of Flagellates 201 



2. THE HAEMOSPOBIDIA 



The evidences upon which are based the claims for haemoflagellate 

 affinities of the Haemosporidia are slight in the extreme. The oc- 

 casional and accidental presence of minute granules which take up 

 nuclear stain has been hailed by Hartmann and his followers as the 

 sought-for second nucleus. A granule which may appear in one indi- 

 vidual among many, which is at no time connected with a motor ap- 

 paratus, and which neither is related to the division of any pai-t of 

 the cell, nor has ever shown any signs of division itself, requires a 

 great deal of imagination to transform it into the homologue of the 

 permanent cell organ of the trypanosomes. 



Woodcock, in his earlier work (1909, 1910) on the Halteridium of 

 the little owl, was inclined to agree with Hartmann 's ideas of the 

 flagellate affinities of these forms, but as the result of further investi- 

 gations (1912, 1914) his views on this subject have entirely changed. 

 In his opinion the extra-nuclear body, prominent during some periods 

 of the life-cycle on the periphery of the nucleus, is the karyosome of 

 the nucleus and not the homologue of the parabasal body of the 

 trypanosomes. Its function is not that of a locomotor component, nor 

 is there any evidence that it stands in any relation to the kinetic 

 activities of the cell, a point which is of very great importance. 



As the same author has shown (1912), the nuclear conditions found 

 in Halteridium are present also in Karyolosus lacertae and Lcucocy- 

 tozoon ziemanni. 



A criticism might be made here which applies euqally well to much 

 of the literature relating to these forms, that is, the uncritical use of 

 terms taken from the cytology of the metazoan cell, where definite 

 structures with definite functions are denoted, and applied to all sorts 

 of vague organelles in the Protozoa which, neither by analogy nor 

 liomology, have a well proven relation to the organs denoted by those 

 names in the metazoan cell. The application of the word centrodcs- 

 mose to any fibril connecting two granules which are not in any way 

 related to the division of the cell, is an example of this. This word 

 was coined by Heidenhain (1894) to designate the achromatic element 

 in which the centrosome or centriole in the metazoan cell is imbedded, 

 and which connects the daughter centrosomes at the time of division, 

 presumably forming part of the central spindle. It is as permanent 

 as the centroseme and takes an active part in the division of the cell 

 and its nucleus. 



