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Dermacentor vmiah ills 
Hosts. Specimens have been taken on man, cattle, horses and dogs. 
I have no record of other hosts for Manitoba. 
Copulation. Copulation has not been observed; presumably it 
takes place on the host, as about an equal number of males and females 
seem to occur on the animals, as is the case in other species of Der¬ 
macentor. 
Oviposition. The act of oviposition was observed several times and 
appears to be similar to that of other species of ticks. One point 
which seems worthy of note is that no matter how slightly gorged a 
female is when removed from the host, she will lay a few eggs. The 
tenacity to life possessed by these partly gorged females is remarkably 
great as compared to that of fully gorged and ungorged females. This 
applies also to D. alhipictus and D. venustus. 
Lai'vae. When first put on to a rabbit, the larvae do not seem to 
feel at home and in every instance many of them have wandered away 
from this host. In my last- experiment I spent fully an hour lifting 
them back with a brush, at the end of which time no more appeared to 
be coming off and, as events proved, they remained to gorge. Owing 
to my early failures I began to think that rabbits were unsuitable 
animals on which to feed the ticks, especially as I read of other workers 
having similar difficulties. Accordingly, a number of larvae were placed 
on a fowl; they at once became extremely active but absolutely refused 
to remain on the bird. 
I do not know on what animals the larval and nymphal stages are 
generally passed in nature; I can only say that it is possible to raise 
them on rabbits in the laboratory. During the period when they are 
not upon the host the immature ticks appear to require moisture. In 
the laboratory it was found necessary to place pieces of moist filter 
paper into the tubes in which they were kept. 
Nymphs. One peculiar feature I observed about the last moult is 
that after the gorged nymphs had been put away for a few days, small 
whitish droplets were seen exuding from their bodies. I at first thought 
some sort of slimy mould was growing on them and washed it off with 
clean water, but as it soon reappeared I examined it under the micro¬ 
scope and found that it was a mucoid substance and contained neither 
bacteria nor moulds. This secretion may serve as a protection against 
desiccation, especially as the climate of Manitoba is dry. Shortly after 
the secretion was noticed the skin began to turn white near the 
capitulum. 
