. 59 



Mites, were sluggish in their movements. On the other hand, all 

 Cannibal Mites that I am acquainted with, are, in the adult state, 

 exceedingly active, and run with astonishing rapidity for creatures of 

 their minute size. 



I think it not improbable that there are several distinct species 

 of Mites that prey upon these Bark-louse eggs. I have descriptions 

 in my journal of adult Mites, belonging to what seem to be four 

 distinct species, two of which were merely found running about 

 among the scales, one was found under a scale where one-third of the 

 eggs were white and plump and the rest yellowish and shrunken, and 

 the other one under a scale in company with two Mite-larvse, that 

 were undoubtedly preying upon the eggs of the Bark-louse. As is 

 usual with Mites arrived at maturity, there was no distinct trans- 

 verse suture, dividing the head-thorax from the abdomen, in any of 

 these four. I have not been able to succeed in rearing any of the 

 Mite-larvae found under the scales to the adult state; so that I will 

 mercifully forbear for the present inflicting upon the general reader 

 long descriptions of adult Mites, which, although they were certainly 

 some of them found under very suspicious circumstances, yet cannot 

 be positively proved to, prey upon Bark-louse eggs, and in any case 

 cannot be identified with the larvae that I know to prey upon these 

 eggs. Not improbably, some of what I have supposed to be distinct 

 species of adult Mites, may be merely the two sexes or two different 

 stages of one and the same species; or very possibly, as is common in 

 several families of insects, species of Mites, which are perfectly dis- 

 tinct in the adult state, may be undistinguishable in the larva state. 



I have only to add, by way of caution to the reader who may 

 desire to verify the above new and very curious facts, that these young 

 Mites, being so nearly of the same size, shape and color as the eggs 

 of the Bark-louse among which they are found, and being also exceed- 

 ingly dull and inactive in their movements, are not very easily 

 recognizable. By long and attentive watching, however, and by try- 

 ing several scales one after the other, a leg or two will at last be 

 perceived, even under a common pocket magnifier, lazily flopping 

 about; and even when the legs cannot be seen, a good lens will often 

 discover the transverse suture across the body of the young Mite, 

 which of course is not to be seen in the unhatched egg of the Bark- 

 louse. It will be found that the shrunken eggs recently preyed upon 

 by the Mite are of a yellowish color; while the empty egg-shells 

 (from which the young lice have hatched out,) that are constantly 

 met with under old last year's scales, are at first, not of a yellowish, 

 but of a transparent white color. It is therefore among such 



