92 
Haemoflagellates , etc. 
introductory remarks Woodcock states, that although the trypanosomes 
possess a common uniform type of organisation, they probably do not all 
belong to a single well-defined group of monophyletic origin, but are 
better regarded as an assemblage of forms which have sprung from quite 
different stocks. Their resemblance he regards as being brought about 
by the acquirement of similar adaptations to similar highly specialised 
modes of life. Later on we shall see that there is at present very little 
evidence in support of the many hypotheses on the origin of these 
parasites. 
Haemoflagellates with two flagella, one directed anteriorly, and the 
other attached to the body of the parasite by an undulating membrane, 
Woodcock regards as being derived from a Heteromastigine ancestor. 
Those flagellates which only possess a single flagellum being derived 
from a Monadine ancestor; some of these however are to be looked upon 
as originating from a Heteromastigine form. All these flagellates possess 
a principal nucleus named by Woodcock the trophonucleus, and a 
smaller chromatic body, the blepharoplast, which Woodcock has named 
the kinetonucleus. The parasites divide by binary longitudinal fission 
or by multiple segmentation; very little how T ever is known of their life 
cycles. The author gives a short account of the earlier work that has 
been done on the structure and life histories of the trypanosomes and 
pays a warm tribute to the great value of the Romanowsky stain and 
its many modifications. This is pleasing to read from the pen of a 
zoologist, as it was feared these valuable stains would have been con¬ 
demned for the more recent wet methods now in vogue. 
In the next section, Woodcock deals with the occurrence and trans¬ 
mission of trypanosomes, and notes that so far the majority have been 
found in mammals, birds and fishes, but a few have been described from 
amphibians, while among reptiles their occurrence has only been 
observed in one or two instances. In a recent paper Wenyon (1908) 
has described an interesting flagellate from the blood of a snake, 
Erythrolamprus aesculapii ; this parasite is very suggestive of a true 
Grithidia. We are however at present unable to express a definite 
opinion on its nature. 
Woodcock draws attention to the distinction between the true or 
natural hosts of trypanosomes and the strange or casual ones, and notes 
that when certain trypanosomes are injected into strange hosts, the 
latter readily succumb. This is naturally to be expected; it is difficult 
to understand any trypanosome not being pathogenic although the 
lesions it produces may not be gross. On more than one occasion we 
