112 
Haemoflagellates , etc. 
Cambridge, is probably also acquired by the larvae; in Madras we have 
seen these spirochaetes in great numbers in the alimentary tracts of the 
larvae of Gulicines. 
Bearing the above facts in mind, it is in the highest degree probable 
that Schaudinn’s mosquitoes were infected with one or other of the 
flagellates we have referred to above, and, in addition, we can find 
nothing in his paper to show that he excluded Spirochaeta culicis. 
Schaudinn found masses of flagellates rolled up in bundles and 
collected in various parts of the alimentary tract of Culex pipiens. 
Anyone who has studied these flagellates of mosquitoes knows that 
they are similarly found in bundles in different parts of the digestive 
tracts of the insects. Then again certain of Schaudinn’s figures clearly 
depict the non-flagellate stage of Herpetomonas , and others, stages in the 
development of a Crithidia. Apart therefore from the possibility of his 
mosquitoes containing the trypanosome, spirochaete, halteridium and 
leucocytozoon of the owl, we believe the gravest source of error in 
Schaudinn’s experiments lies in the fact that the insects may have also 
contained two flagellates and a spirochaete. Assuming then that his 
mosquitoes may have harboured no less than seven parasites, we are at 
a loss to understand how any investigator, even with Schaudinn’s great 
technical skill and phenomenal powers of interpretation, could possibly 
follow any one of the parasites through a complicated developmental 
cycle; we know from experience that the resulting confusion would 
be exceedingly great. 
It is generally stated (see Mesnil, Bull. Inst. Past. v. 3, 1905, 
pp. 363—367) that Schaudinn actually saw a Halteridium ookinete 
become a trypanosome presumably in the blood from the mosquito’s 
stomach, and that the melanin granules helped to trace the stages in 
the evolution. With regard to this statement, we would like to point 
out that we have seen a leech Crithidia in its pre-flagellate stage con¬ 
taining melanin-like granules, and that if such a cell be studied, apart 
from its flagellate stage, it may quite well be mistaken for an 
intracellular pigment-containing parasite. It should therefore be borne 
in mind that these flagellates of invertebrates may contain pigment-like 
granules. Could it be possible Schaudinn was dealing with the pre- 
flagellate stage of a Crithidia ? 
We have noted above that in a footnote (p. 239) Woodcock states 
that he has at length obtained the first definite and unmistakable 
evidence in favour of one of Schaudinn’s conclusions. As a result of his 
observations on a Halteridium of the chaffinch, he has no doubt that in 
