102 W. COLE OX A PARASITE OF HUMBLE BEES. 



various other nematoids. Siebold's experiments have shown that 

 young worms of this class are capable of living in moist earth, and 

 there becoming sexually mature, and it has been conjectured that 

 it is in this stage the great work of reproduction is commenced. 

 The males are observed much more rarely than the females. Mr. 

 Lewis, for instance, in the paper I have before referred to, says 

 there was not one male amongst the 50 or 60 specimens of Mermis 

 he possessed ; I believe Van Benedin's opinion is that the males 

 quit their hosts some time before the female, and if so, the habit 

 furnishes a reason for the apparent scarcity of the former. 



From Sir John Lubbock's and my own experiments, it is certain 

 that young Sphcerularice are capable of living for many weeks in 

 water after removal from the body of the bee, and we can imagine, 

 with a degree of probability, that the natural history of the bee- 

 worm may be somewhat in this wise. — Although I have not myself 

 observed any diminution of vital power in the infected bees, they 

 must doubtless in time become weaker and weaker from the ab- 

 sorption of the vital fluids by their insidious foes, and then crawl- 

 ing into some grassy nook where the soil is soft and damp, quietly 

 end their busy lives. The young worms then probably quit their 

 victim, and take up their abode amidst the moist earth and herbage. 

 If Schneider's theory is correct, it is here, perhaps, that the union 

 of the sexes takes place, the young nematoids becoming mature 

 after leaving the bee; but, if the other view of the case be the true 

 one, this event is probably deferred until the male and female are 

 safely lodged in the interior "of a new "host." In any case, the 

 worms would await the arrival of some wandering Bombus, 

 in which case the bee, groping amongst the herbage, as is the 

 habit of its tribe, " poking its nose into this and to that," could 

 hardly fail to come into collision with some of the expectant 

 nematoids ; they would lose no time in taking up their local habi- 

 tation in the insect's body, and then by growth during the winter, 

 assume the form in which we find them in the spring, so once more 

 completing the cycle of their existence. 



If something like the above be their habits, their chance of life 

 is dependent on a humble-bee accidentally blundering into their 

 place of concealment, and thousands must inevitably perish without 

 ever having had an opportunity of entering an insect. In Nature 

 we often find vicissitudes of a like description in the life of a plant 

 or animal, compensated for by great powers of increase under 



