Beck, on the Metamorphosis of a Coccus. 49 



I am unable to say as mucli of the female, though I presume 

 such must be the case, as only a perfect insect is capable of 

 reproducing its species. I have not as yet paid as much 

 attention to this sex, but so far as my investigations have 

 gone, after it has changed into the pupa state all external 

 organs entirely disappear, excepting those at the extremity of 

 the body, and the proboscis, which becomes stronger and 

 larger (fig. 8) ; the secretion of the shield is continued until 

 nearly four or five times the size of the male, and the body of 

 the insect bears about the same proportion ; it then deposits 

 '.ts eggs, between one and two hundred in number, which are 

 placed on end in great regularity, and the first ones will 

 frequently be found hatching before the last are laid. 



The external surface of the shield of the male (fig. 7) gives 

 very marked indications of the three changes that have taken 

 place : first, there is the cast skin of the larva ; secondly, the 

 shield for the pupa ; and thirdly, a thin and short addition to 

 the shield for the wings of the imago, which I believe is lifted 

 up when the insect escapes. 



There are also three similar indications on the external 

 surface of the female shield, and these may also warrant the 

 conclusion that its metamorphoses have been complete. 



It is somewhat surprising that these cocci are to be found 

 in a living state at all, after the change they must have ex- 

 perienced in the climate ; it is, however, very evident that the 

 larva and pupa states are much hardier than that of the 

 imago; at least so far as the males are concerned, I have found 

 it very difiicult to obtain any alive after the external organs 

 were fully developed. As it is, the circumstances under which 

 they appear are very favorable to their examination ; one 

 single orange, if well selected, will supply every condition I 

 have mentioned ; and I imagine that from the fact of the shield 

 being such a complete protection, the metamorphoses are 

 more distinct in their development than under the more 

 ordinary circumstances where the insect itself is exposed. I 

 have invariably used Mr. Wenham^s binocular arrangement 

 with the microscope, and I can only say that for this class 

 of investigations the results are perfectly marvellous. 



