294 



MB. A. D. MICHAEL ON THE LIFE-HISTORIES 



move about very slowly; but the day after it bad collapsed and 

 was dead. There was now only one llypopus left ; tliis did not 

 move nor show any sign of life ; but, on the other hand, it did 

 not collapse, and in this condition it remained for nearly four 

 montlis. I w^atched it every day without seeing any change 

 until the 24th May, 1886, on which day a healthy nymph of G. 

 spinipes emerged from the Hypopial skin. 



While this experiment was progressing I had also watched the 

 cell in which I had placed the cases : one nymph of G. spinipes 

 had appeared in the cell and one case was open at the posterior 

 end ; otherwise there was not any change. But on the 26th May 

 I found two more cases open and two Hypopi had apparently 

 crawled out of them ; on touching these Hypopi they appeared 

 inert and incapable of motion, but a few days after nymphs of 

 G. spitiipes emerged from them. 



In October 1887 I again obtained more material from the 

 same chaff-house, and also from another farm some fifty miles 

 distant from the first ; this latter contained G. domesticus. In both 

 samples the Glyciphagi were numerous and the larvse and nymphs 

 were abundant, but I could not find any cases or any trace of 

 Hypopi in either. 



In January 1888 I once more took up the investigation : I 

 obtained material and sweepings from the same chafE-house and 

 again found the reticulated cases of G. spinipes; most of them 

 were open at the posterior end, the occupants having emerged. 

 I put seven of the full cases in a separate cell ; in one of these 

 cases I could easily distinguish a Hypopus moving its legs. I 

 also found one which had apparently come out of the case, and 

 which was capable of the same amount of motion ; it was from 

 this specimen that fig. 9 was drawn. On February 6 I found 

 that one of the seven cases was open and that a nymph had 

 emerged from it. I isolated this in another cell, which I will 

 call cell 5. On February 8 another nymph emerged from a second 

 of the seven cases. I placed this nymph also in cell 5. On 

 February 9 an adult G. spinipes emerged from one of the nymphs 

 in cell 5, the second nymph also was inert. On February 26 an 

 adult of the same species emerged from the remaining inert nymph. 



From this time up to the end of April, wheu I closed the 

 observations, nymphs of G. spinipes continued to emerge at inter- 

 vals from the remainder of the seven cases, and from other cases 

 which I had put in different cells, and adults continued to emerge 



