FIRST ANNUAL REPORT OF 



and August, any of you may find the true louse underneath, occupy- 

 ing but a portion of, and being quite separate from it. 



From analogy we may presume that there are males as well as 

 females of this species, since winged males are known to occur in the 

 genus Aspidiotus, and it has been my great aim and hope to discover 

 this gentleman. Though an extremely small percentage of the scales 

 may generally be found dwarfed and empty during the first days of 

 August, suggesting that a male may have escaped, yet as likely as not 

 these may have been killed by some cause or other. In the latter 

 part of June I counted five hundred scales on a single twig, and 

 marked them to prevent mistake or confusion in recognizing them 

 again. After watching them steadily, and carefully lifting each one 

 on the 28th of August, they all, with the exception of two, were found 

 to contain eggs. The same average would doubtless have been found 

 over the whole tree ; and from this fact I am constrained to believe 

 that as a rule no males appear, and that if there be exceptions where 

 they do occur, they are in such proportion as to be of little avail. Mr. 

 Shimer, in speaking of the Clinton grape gall, already alluded to, 

 states that he opened thousands of them before he found a male ; and 

 it is difficult to conceive what effect a single delicate male, shut up 

 in a gall, could have on the thousands of others not dignified by his 

 presence. When we reflect on the abnormities occurring among our 

 plant-lice, I see no reason why our bark-lice should not be herma- 

 phrodite as a rule, and yet occasionally produce males. They are still 

 lower in the scale of Nature than the plant-lice, and one of them — the 

 celebrated Cochineal — puzzled naturalists a long time as to whether 

 it was a plant or an animal. There is in fact so much of the anoma- 

 lous about this family that it furnishes a rich and interesting field 

 of study. 



The observations of both, Mr. Shimer, Mr. Walsh, and myself 

 agreed as to the time of hatching ; as to the mode of growth of the 

 scale, and as to finding no females ; but as to the process by which 

 the scale was formed there was difference of opinion. The reason, it 

 seems to me, is obvious enough : in attempting to elucidate the pro- 

 blem we reach beyond the limits of our power of perception into the 

 realms of conjecture. It is easy enough to watch the mode of growth 

 of an oak-apple, but it is not such an easy matter to ascertain the 

 reason why the kind which occurs on the red oak (produced by Cynips 

 quercus-inanis) should form inside with radiating spokes from a com- 

 mon central cell; while that on the black oak (produced by Cynips* 

 quercus-spongifica) should form inside with a dense spongy substance 

 around a similar central cell. Mr. Shimer may, in part, be right in 

 stating that the larval scale is formed by the young louse shedding its 

 skin; but the extremely fine skin alone would not form such a 

 scale, and he strangely overlooks the wax-like filaments secreted 

 from the general surface of the body as well as the peculiar dis- 

 tinction in the growth of the "medial" and "anal" sacks. That these 



