16 
W. L. WILLIAMS. 
lives for four or five days, if protected by the tissues from desic¬ 
cation. Placed in a normal salt solution, the parasites quickly 
cluster together in an intricate mass and either remain swim¬ 
ming on top of the solution, or descend to the bottom of the 
vessel, in either position keeping up almost constant movements 
of the feet and rostra, without appreciable change in the loca¬ 
tion of the clump. If one be separated from the cluster it usu¬ 
ally rejoins it promptly. In this condition they live and remain 
apparently quite vigorous in a room at about 70° F. for a period 
of five to eight days. They appear to be quite indifferent as to 
whether submerged in water or floating on its surface. Re¬ 
moved from moisture, they quickly dessicate and die. 
There is great variation of opinion among the different 
observers as to their power to cause serious disease. 
Gerlach and Zundel were alike positive that they caused 
serious losses among the poultry of their clients, while Megnin 
and others are as certain that the former were in error and that 
it is only possible for them to do great harm when collecting in 
great masses and blocking up the air passages ; a very rare 
occurrence. 
Gerlach thought the enteritis he observed was most likely 
due to migrations of some immature or larval form boring its 
way through the tissues, but Megnin very properly states that 
this cannot be, as the mouth tissues are tubular, that the para¬ 
site can only suck up fluids about it and is utterly incompetent 
to burrow in or through the tissues. When it is remembered 
also that the entire development of the parasite from ovum to 
six legged young, can be watched in the body of the female, in 
which state, if not in its eight-legged form, it is born with mouth 
parts like the adult, it is evident that we see the entire life cycle 
of the mite and that at no date in its history is it able to 
burrow or bite ; and since the body and extremities are practi- . 
cally free from any hairs or projections capable of inducing any 
severe wounds or abrasions, it must be admitted, as Megnin 
states, that no serious results should follow their presence in so 
far as mechanical irritation is concerned. 
