the 'Economy of the Strepsiptera. 167 



those authors who have considered that the Stylops deposits her 

 eggs between the scales of the abdomen of the perfect bee. It is 

 known that the Stylops appears at the same time of year as the An- 

 drence, a fact which has evidently led to the adoption of such 

 idea by those who have not calculated the impossibility of such 

 a mode of proceeding ; since, if such were really the case, one or 

 other of two very different species of economy must be adopted, 

 both of which militate against the general rules of insect life ; for 

 either the development of the Stylops must be so rapid as to take 

 place during the short life of the Andrena in whose body the eggs 

 have been deposited, or its development is slow and the bee remains 

 alive till the following spring. But against these opinions it may be 

 urged that we should be compelled, with respect to the former, to 

 advocate that the Stylops being arrived at its perfect state in spring, 

 must necessarily survive the winter in order to deposit its eggs at 

 the commencement of the following spring in the newly disclosed 

 bee, a circumstance which the tender construction of the Stylops 

 completely prevents ; whilst against the latter the well-known short 

 life of the Andrenm, and the fact now ascertained that bees are sty- 

 lopized previous to leaving their cells, and which could not happen 

 were we to adopt the latter idea, may, without fear of contradiction, 

 be asserted. 



Having proved that the Stylops cannot deposit her eggs in the 

 perfect bee, and that it is impossible for it to make its way to the 

 cell of the Andrena so as to lay its eggs in the larva of the bee, 

 which are not born until after the cell is closed, I will now offer 

 to the consideration of the Society the circumstances which appear 

 to me to take place in regard to the dejDosition of the eggs of the 

 Stylops, and which are founded on the necessary consequence that 

 they must be laid in the cell previously to its being closed. Whether 

 indeed it is in the cell itself that the eggs are deposited, so that the 

 larvae of the Stylops when born may make their Avay into the body 

 of the larva or pupa, or even into the perfect bee, or whether they 

 are actually deposited in the egg of the bee, we have no means at 

 present of determining. I may however be allowed to mention 

 that at the first I felt strongly inclined to adopt the supposition 

 that the former of these opinions was the correct one, and that the 

 larvae when born made their way into the body of the larva of the 

 bee ; but not being able upon an examination of what is generally 

 considered to be the larva of the Stylops to discover any organs by 

 which it could effect this purpose I was obliged to give up this idea, 

 and adopt the startling theory that the Stylops deposits her eggs in 

 the egg of the Andrena. 



o 2 



