294 Dr. T. A. Chapman on What the 



posterior portion of tlie gut, full of a dark material. It 

 measured iVO nnii. in length and over 0'5 mm. in thick- 

 ness. It was rather hard and solid and so remains, as I 

 have not broken it up, but mounted in Farrant's medium 

 its structure is fairly evident. Further forwards in the 

 gut were also portions of contents. These were soft and 

 easily pri'sscd flat on a slide. 



The ])os(erior ])orti()n of the dark mass is rather shorter 

 and more slender tli.'in the forward portion. It presents 

 a quantity of granular material in layers of darker and 

 lighter appearance. It might, though I hardly expect 

 it, yield some structural material from which some in- 

 formation would result were it brok(>n up; for the present, 

 however, 1 have not done so. The forward portion seems 

 to consist of a mass of minute hairs, of fairly uniform size 

 and structure. 



The less dense material found further forwards in the 

 gut presents a mimber of identical hairs, but also some 

 small triangular chitinous bodies very like mandibles of 

 some insect. 



Mr. Donisthorpe having told me tluit the ant with 

 which r found the larva was Myrmica scabrinodis var. 

 S(ibi<lcli., l)rought to my recollection that last year I had 

 examined and mounted specimens of the larva of Mywiica 

 ficobrivodis. Tliese came in, now. most usefidly, and, to 

 make a long story short, a comparison of the larval skin of 

 M i/rniica scabrinodis, iiud of the contents of the alimentary 

 canal of my example of the larva of L. orion, showed that 

 the hairs in the avion agreed precisely with those of the 

 full-grown larva of M. scabrinodis, and that the chitinous 

 triangles agreed exactly with the mandibles of the same 

 hirva. 



Nothing of a vegetable character was found amongst 

 these contents, and it could not be doubted that the L. arion 

 larva had eaten many larvae of 31. scabrinodis and nothing 

 else for a long time. 



The dark mass of dejecta in the lower gut suggests several 

 (piestions. First, perliaps, it seems liiglily jnobable that 

 the larva of L. arion in its last instar behaves as do the 

 larvae of many bees and wasps, various parasites, such as 

 McloecHs and other insects, that live on material that is 

 practically all digestible, and contains very little etfete 

 material; that is, it does not, until it has completed its 

 growth, evacuate any of the contents of the gut, but allows 



