and Relations of the Wasp and Rhipiphorus. 351 



angle of the cell higher up. I have tried my best to find a 

 difference between the two eggs, but without success. I am 

 not sufficiently acquainted with the economy of wasps and bees 

 to know whether the queens often or ever commit the mis- 

 take of laying two eggs in the same cell: it may happen 

 sometimes ; but when it does happen, one would expect to 

 find the mistake at long and wide intervals, not in a cluster or 

 near each other, unless, indeed, we are to suppose that the 

 queen only makes the mistake when she is in a stupid or ab- 

 sent frame of mind ; for then the mistakes should all be near 

 each other. This, however, seems less likely, because the exer- 

 cise of instinct is not like that of pure mental effort. A man's 

 instinct will lead him right when his reasoning fails him. 

 Every one must be able to recall to his mind some time or other 

 when he has instinctively found liis way home although his mind 

 has been so preoccupied as to take no note of external objects ; 

 and absence of mind would therefore be immaterial to an 

 insect engaged on an operation of instinct. Now in the combs 

 containing eggs the doubly employed cells were located near 

 each other ; and that I should be inclined to regard as a primd 

 facie presumption that one of the eggs was not that of the 

 wasp, but of RMpi])horus. 



Should that be so, the points of resemblance in the economy 

 of the Rhij)iphorus to that of the wasp would become very 

 striking. We should have : — 



1. The &g^ of the same size, texture, shape, and transpa- 

 rency in both. (I am not quite positive about the enclosed 

 undeveloped larva being quite the same. I have thought that 

 in Canada balsam, which makes the shell transparent, the one 

 seemed longer than the other ; but this may have been due to 

 state of advancement or imperfect observation.) 



2. We should have the q^q attached in the same way, at 

 the same height in the cell, and in the same angle as it is 

 placed by the wasps. 



3. The larvjB must feed on the same food as the wasp-larvse, 

 and deposit similar black droppings ; for these are found in the 

 RM^^ijjhort-ceWs as well as in the wasps', and are un distin- 

 guishable from them, consisting of debris of digested insects, 

 which might with care be often identified. In the hornet, 

 where the fragments are larger, the identification of most of 

 them can be made without much difficulty. Miss Eleanor 

 Ormerod shrewdly remarks to me, however, that she has ob- 

 served that, unlike the wasps, the dead pupse of the Rhipi- 

 phorus keep well in their cells, and that this may be due to a 

 difference of food. But we must remember that their texture 

 is naturally harder and drier. 



