468 On the Eggs of Covixa Mercenaries. 



The esrgs given to me by M. Virlet were in the state in 

 which they are usually collected. They had been dried in the 

 sun, but not ground, so that their microscopic structure could 

 be examined as well as their chemical composition. 



First, with regard to the latter, they have yielded me : — 



Water 0*8 



Mineral matter 5*0 



Organic matter, consisting almost exclusively 



of Chitine . . . / 94'2 



100-0 



Nitrogen (per cent.) 6*2 



The mineral matter, or ash left after incineration, contains 



much phosphate of lime, it contains also carbonate of lime, 



oxide of iron, soda, and silicic acid. 



A B C Yhe quantity of material in my posses- 



l \ f\ s * on being so small, precluded the 



V"C^ W \Lj possibility of a quantitative analysis of 



<b X the ash. The organic matter, amount- 



A. Natural size. ing to 94'2 per cent., consisted almost 



B. Magnified. entirely of Chitine ; this curious fact 



C 'la I rTa. egg **" "^ * ** WaS fu % ex P lained wnen the e g? s were 

 submitted to microscopical examination. 



It was found that the larvce had quitted them. Nothing- 

 remained but the rigid envelope of the egg, and its singular 

 little appendix, by which each egg adheres to the surface of 

 the reed. (See Fig.) 



Under the microscope, with one quarter inch object-glass, 

 the eggs of the Corixa do not differ in appearance from those 

 of a chicken, but underneath the wider extremity of the egg 

 exists a little appendix, in shape like the foot of a wine-glass, 

 which I do not find mentioned in any work on comparative 

 anatomy, and does not seem to have been observed before. 

 The oval portion of the egg appears to be formed of Chitine 

 and mineral matter containing much lime. The little appendix 

 is formed of Chitine alone, and under the microscope appears 

 like ordinary gelatine. The larva leaves the egg by a circular 

 stellated orifice formed at its narrow extremity. 



From what precedes, it would appear that the flour formed 

 by grinding these eggs of the Corixa must be of a most nutritious 

 nature : — The amount of nitrogen found in the analysis is very 

 large, and agrees nearly with the known composition of Chitine. 

 For it is impossible to admit with M. Fremy that Chitine is a 

 substance analogous to cellulose. In his experiments upon the 

 former, he boiled it with solution of potash, in order, as he 

 stated, to eliminate the albuminous compounds which he sup- 

 poses associated with it. It is very much more probable that 



