Mr. H. J. Carter on the Natural History of the Lac-Insect. 7 



in the replacing of the two hairs growing from the penultimate 

 segment on either side of the tail by two delicate, white, twisted 

 cords, composed of the attenuated extremities of the tracheae. 

 There are further differences between the sexes at this period, in 

 the female having lost all traces of eyes, antennse, and legs, 

 whilst, no differentiation having taken place between the head 

 and body, the female is reduced to a mere elliptical sac, with but 

 faint traces of the original segmentation. From the thorax, how- 

 ever, project the two tufts of white tracheae, which are absent in 

 the male, and also a tuft from the anal extremity, the two hairs 

 before alluded to (fig. 4<b b) having disappeared altogether ; but 

 the row of hairs round the anus, which are now absent in the 

 male, still remain in the female (fig. 11 bb), and appear to serve 

 the purpose chiefly of preventing the secretion of lac from cover- 

 ing up the anal aperture. 



At this period only, the bodies of both male and female are 

 about the same size (viz. about l-27th of an inch long) ; but while 

 the former has become more highly developed and eliminated, 

 for the performance of his special function, the latter has be- 

 come retrograde and permanently incarcerated for hers. So 

 unsparingly does Nature deal with her forms for the develop- 

 ment of the new being ! 



Impregnation. — After having taken home the small portion of 

 the branch above mentioned, which was covered more or less 

 with the newly incrusted brood, on which there were no free 

 males, I was astonished, on taking it up an hour or two after- 

 wards, to observe that two had made their appearance, and were 

 actively engaged in impregnating the females. This they do by 

 drawing the organ before described downwards and a little for- 

 wards just over the hole in the lac which leads to the anal orifice 

 of the female, and then inserting it ; after which the male sits 

 on the hole, as it were, for a few moments, and then, withdraw- 

 ing the penis, goes to another female, and so on till his office is 

 fulfilled. 



I now watched the process for some time ; and having suffi- 

 ciently satisfied myself of the fact as just stated, the two males 

 were removed for microscopical examination, and the branch left 

 as before without any. Next morning, to my astonishment, I 

 again found two more males on it, actively engaged in perform- 

 ing their duty like the former ones ; and then it struck me that 

 they must come from some of the incrustations ; so I examined 

 the latter, and soon saw that there were two distinct kinds of 

 incrustations on the bark, — one (fig. 14) circular, slightly larger 

 than the other, and, when isolated from the rest (which for tlie 

 most part are agglomerated), presenting twelve notches or teeth 

 symmetrically arranged round the base, six on each side, with 



