ANTLER MOTH PARASITES. 17 



all, when they first came, to have these hairworms within them ; now 

 there is only an odd one." 



On the 16th of July Mr. Gray forwarded me more specimens of 

 these Hair- or Thread-worms, which proved to be Nematoid worms of 

 the genus Mcrmis, with the remark, " I send you some more cater- 

 pillars, also two of the Hairworms and one maggot" ; and on the 12th 

 of August Mr. Gray wrote further, still noticing the perishing of the 

 chrysalids, and also presence of a disease which turned the caterpillars 

 black, hard, and brittle. " I am sorry to say that the chrysalids I had, 

 which I was watching, have all been spoilt. I have been wondering if 

 the caterpillars and the Voles were in any way connected, as in 1891 

 and 1892 the Voles were very bad in this district, and sometimes these 

 pests lead up one to another." ..." Some of the caterpillars I found 

 were the full length, and black and quite hard, and on breaking them 

 I found them full of a reddish liquid." . . . 



Parasites. — The very long filiform worms, of which specimens 

 were sent me by Mr. Gray, and which I also found alive in the Antler 

 Moth caterpillars, proved to be Nematoid, or " Threadworms," of the 

 genus Mermis. They were transparent and whitish, and, unless highly 

 magnified, appeared only like a long white thread, but with great 

 power of contorting themselves into an elaborate knot. The longest 

 Threadworm which I managed to extract (so far as I could ascertain 

 unbroken) was about eight inches in length, and from the same cater- 

 pillar I extracted a piece of Threadworm six and a quarter inches, and 

 another about four inches long. As I could not trust to my own 

 identification of Nematode worms, I forwarded several specimens to Dr. 

 J. Ritzema Bos, Professor at the Royal Agricultural College, Wageningen, 

 Netherlands, who was good enough to inform me that the Threadworms 

 were certainly of the genus Mermis, and apparently Mermis albicans, 

 v. Sieb., but this [i.e., the species) he would not state positively, the 

 part V. of the ' Zeitschrift fur wissenschaftliche Zoologie,' in which 

 this species is described, not being then at hand. 



These Mermis live in the body-cavity of insects, and escape into the 

 damp earth, where they come to sexual maturity and pair ;'*'■ and in 

 this same paragraph (see reference below) it is stated that v. Siebold 

 established by experiment the fact of the migration of the embryos of 

 the Mermis albicans, v. Sieb., into the caterpillars of the small moth, 

 the Tinea evonymella, a small yellowish-grey caterpillar, with black 

 spots, which lives on the Spindle-tree, which is of interest, as giving a 

 precise record of their presence in one kind of lepidopterous larva. 



"Flacherie." — Of the feyf Char ceas graminis caterpillars which I 

 was able to forward to Dr. Ritzema Bos, he further remarked, " One 

 was attacked by 'flacherie' — 'flaccidezza' — a disease which is also 



* See ' Text-book of Zoology,' Clans & SeclgW-ick, vol. i., 2ncl Edition, p. 356. 



C 



