W. S. Patton 
117 
How then can these invertebrates be second or intermediate hosts of 
various vertebrate flagellates ? As far as we know there is no proof to 
show that the common house fly has descended from a blood-sucking 
ancestor, and that H. muscae domesticae and the new flagellate we have 
found in its malpighian tubes have been derived from haemal forms. 
The same may be said of Sarcophaga and its flagellates, Lucilia and a 
host of others. 
Woodcock in his remarks on the diphyletic origin of the trypanosomes 
refers the reader to his original ai'ticle (1906, pp. 270—278), where he 
discusses the whole question at length; we shall now examine his 
arguments in detail. Before however doing so, it is necessary to under¬ 
stand our position with regard to this difficult subject. 
We consider Woodcock’s Trypanomorpha noctuae (Schaudinu’s T. 
noctuae ) is nothing more than Crithidiafascicidata and possibly 11. cidicis, 
and that the Crithidia and Herpetomonas of blood-sucking arthropods 
and leeches are true parasites of these invertebrates, and therefore do 
not represent part of the life cycles of vertebrate trypanosomes. In 
support of his views Woodcock lays particular stress on certain biological 
and morphological conditions. Under the first heading he says that the 
sensory extremity of a Haemoflagellate is its anterior end, and that T. 
ziemanni, in its resting stage, attaches itself and penetrates a leucocyte 
by its non-flagellate extremity. The parasite referred to here is 
Haemamoeba ziemanni, Laveran, which Schaudinn regards as being but 
the stage of a Spirochaeta. We believe that Schaudinn confused this 
intracellular parasite of the owl with the flagellates of Culexpipiens, and 
more particularly with Spirochaeta cidicis. In any case we do not 
understand what connection this Haemamoeba has with a Haemoflagellate, 
and it is by no means proved that it is a spirochaete. Herpetomonas and 
Crithidia we know always attach themselves to the intestinal epithelium 
of their hosts by their flagella; on the contrary it is not known by what 
means the trypanosomes and trypanoplasmes attach themselves. It 
would be important to know how Crithidia penetrate the eggs of their 
hosts and how Endotrypanum schaudinni penetrates the red corpuscles 
of Cholaepus didactylus. Granting any of the points on the methods of 
attachment brought forward by Woodcock, it is however hardly justifi¬ 
able to draw any far-reaching conclusions from a few doubtful observa¬ 
tions. 
With regard to the process known as agglomeration, we have pointed 
out above (p. 97) that a clear distinction should be drawn between the 
true rosette and a mere agglomeration of adult flagellates ; the former is 
