COCCID.E. 213 



female should be examined for specific points, as the spinnerets and 

 other microscopical characters are not fully developed till after tin- 

 second larval moult ; and no doubt in a general way specific errors 

 have occurred, and are likely to do so, by several workers examin- 

 ing the same species in two distinct stages. 



The male scale (fig. 205 (7)) differs from the female (fig. 205 (6)) by 

 having only one larval moult, by being lighter in colour, felted, more 

 linear, and carinated. The perfect male (tig. 205 (8)) contrasts with 

 the female, inasmuch as it has two wings (though apterous specimens 

 are often found), six legs, and two antennae, two eyes, and no mouth 

 or feeding-organ. The male generally appears about the first week in 

 July, and only lives from about three to seven days, but during that 

 short space of time he has obtained the sole object of his existence 

 viz., the perpetuation of his species. 



The genitoires are large in proportion to the size of the creature, 

 varying from about one-third to one-half the length of the whole 

 insect. We here see the adaptation to environment in the abnormal 

 development of the penis-sheath requisite, considering that the female 

 is stationary and helpless, and covered with a shell ; while we note in 

 her the absence of eyes and legs both useless under an opaque shell. 

 Hence we have a beautiful illustration of the elaboration of one part 

 and the degeneration of others. 



It may be as well to remark that previous to the publication of 

 Kewstead's Monograph this species was known as Cluonaspis fraxini, 

 Sign., but this and several other so-called species have been sunk as 

 synonyms of C. salicis. 



In order that the student may thoroughly understand the life- 

 history and structure of this important arboreal insect, it may be 

 advisable to give a short epitome of the foregoing description, as 

 illustrated by "figs. " in figure 205. In fig. 1 we have a single egg. 

 The eggs are found in winter as represented in fig. 4, and hatch out in 

 May. Fig. 2 represents a larva which is active for a short time ; fig. 3 

 represents the dorsal surface of a fully developed female scale : a is the 

 first and b the second larval moult. The sexes cannot be distinguished 

 till after the first larval moult, and fig. 7 represents the male scale, 

 showing the remains of only one larval moult, together with the 

 secretionary portion ; and fig. 8 represents the fully developed male, 

 which appears in July, and copulates with the female, represented in 

 fig. 5. It should be specially noted that at this period the female is 



