92 Mr. A. Murray on the Relations 



babilitj that the cell should have been opened at that precise 

 conjuncture of time that it began its attack. It is also still 

 more unlikely that, having been sealed up Avitli it, it should 

 not have sooner made its attack. It is so disrespectful to the 

 instinct of the Rhipiphori that the parent should have laid an 

 Q.gg in a cell already tenanted, and within reach of the jaws 

 of the tenant, that I shall not suggest that alternative. 



As to the E/npij)horus-\n\i^9d retaining the skin and mandi- 

 bles of the grub they have eaten in their grasp, which Mr, 

 Stone alleges of this one and of others which he subsequently 

 observed, it is obviously a somewhat ludicrous blunder arising 

 from a confusion of head and tail. I presume that by retain- 

 ing in their grasp, he means holding in their jaws ; they have 

 no legs or claws to grasp with. But he must have forgotten 

 that the parasite began at the head and, of course, finished off 

 at the tail, and that it therefore should not be the mandibles 

 that " it retained in its grasp," but the other end. But it 

 seems to me clear that he had observed the old cast skin of 

 the larva, which lies at the bottom of the cell, sticking to the 

 tail of the pupa, not retained in its mouth. We know that the 

 tail forms a powerful sucker ; and, of course, it sucks up into 

 its cup, like the bottom of a seaman's lead, anything that 

 is lying loose at the bottom ; and we knoAV, too, that the last 

 cast skin of a larva is very often found adhering to the 

 chrysalis. We know, also, that when the larva undergoes 

 its transformation, its muscles undergo a complete degrada- 

 tion, becoming like milk, and all muscular power on the 

 part of the pupa at that particular period vanishes. As 

 the change goes on, the muscular power is restored by the 

 rc-formation or consolidation of the muscles ; but the idea of 

 a pupa holding anything in its jaws by the tenacity of its 

 muscular power seems to me an impossibility. I have only 

 to add that none of my pupte (and I have a number preserved 

 in Canada balsam) has either skin or mandibles in its jaws, 

 but most of them have them still adhering to the tail. This 

 fjict seems to prove that, like my pupa3, Mr. Stone's must have 

 had their lieads to the mouth of the cell, instead of in the posi- 

 tion which his and Mr. Smith's hypothesis requires, at its base. 



Next, as to the second and only other case of nRhipiphorus- 

 larva taken in the act of attacking a wasp-grub. The state- 

 ment is as follows : — " I was fortunate in discovering a small 

 larva of Rhipi'pliorus firmly attached to its victim ; both were 

 dead, and had become partially dried, so that, when immersed 

 in spirits, they did not separate, but remained attached just as 

 they were before death." 



This seems to me to be a case of a double occupation of 



