LUBBOCK ON SPHJ2B.ULARTA BOMBI. 51 



whole race must soon perish. For, if their history were so simple, there 

 seems no reason why a large proportion of young might not survive ; and 

 the species would then continually increase in numbers, which is impos- 

 sible. This argument is, however, far from conclusive, because the in- 

 crease may be prevented by disease, or by some enemy. On the other 

 hand, there would, under this theory, be no means by which the parasites 

 could pass from bees of one nest to those of another; so that in each 

 species we should have one race infested by Sphaerulari, and another 

 free from them; in which case, it can hardly be doubted that the former 

 race would, in the struggle for existence, gradually be supplanted by 

 the latter, and thus, in time, the Sphaerulari would all perish. 



That the young Sphaerulari can live some time after leaving the 

 body of the bee, and without entering any other animal, I ascertained 

 satisfactorily. On the 25th of last May I took some from the body of a 

 B. lucorum and put them in water, where some of them remained alive 

 until the 9th of August, though, during the latter part of the time, 

 they were far from lively. In this case, therefore, they lived in water 

 for more than ten weeks. Whether they would have lived as long in 

 damp earth, I cannot say, but it seems not improbable ; and as we know 

 that humble bees often crawl about on the earth under leaves and grass, 

 they may, in this manner, give the young Sphaerulari an opportunity 

 of entering them. I tried to solve this question, by wetting humble 

 bees with water containing young Sphaerularias ; but, partly owing to 

 the difficulty of keeping these insects in confinement alive for more 

 than a few days, and partly, perhaps, from the difficulty of detecting a 

 single young worm in the abdomen of a bee, my experiments were quite 

 unsuccessful.* 



I had hoped to have thrown some light upon this question, and also 

 upon the metamorphosis, by obtaining some specimens in autumn and 

 winter. Up to the present time, however, I have only found them in 

 May, June, and July. This is partly, perhaps, owing to the fact, that 

 large females are most easily obtainable in these months ; and it is un- 

 lucky for me that the last two years have been very unfavourable to 

 bees — 1860, indeed, so much so, that it is said (Zoologist, September, 

 1860), to have been the worst year for Hynmoptera since 1828. 



I have, however, examined eight large females of B. lucorum in 

 August, and three in October; two of B. terrestris in August, two in 

 September, and two in October ; if, therefore, at this season, the Sphae- 

 rulari were as numerous and as large as in spring and summer, I 

 should almost certainly have found some^ If, on the other hand, they 

 were quite small, they may easily have been overlooked. 



From all these facts, I am inclined to think that humble bees, when 

 infested with Sphaerularia, live for a while as if nothing were the matter ; 

 and that only when the young Sphaerulari, or the majority of them, 



* I found the best plan wae to put the bees in a glass with moist sugar. They seemed 

 also to live longer if put in the dark, probably from the soothing effect upon their nerves. 

 In this manner I kept one bee alive for more than a month. 



