248 SUMMARY OF CURRENT RESEARCHES RELATING TO 



animals never go through all the phases of their development in one 

 and the same organ. 



Notes on Nematoids.* — Dr. J. G. De Man divides his paper 

 under three heads. First, the Netherlands, whence he describes a 

 new species Monohystera dintheriana, which is interesting on account 

 of its having quite bilaterally symmetrical female organs, an arrange- 

 ment not known in any other terrestrial and in only one marine of 

 the many species of this genus ; there are notes on other forms. The 

 second deals with Mid-Germany (the neighbourhood of Weimar), 

 where thirty-eight species were found; of these Dorylaimus etters- 

 hergensis and oxycephalus are new. The third heading is Russia, 

 whence Moscow sends thirty-three species; of these Dorylaimus 

 zograffi is new ; it is most like D. hastiani. 



Sphaerularia Bombi.f — Prof. A. Schneider continues his investiga- 

 tion of this singular parasite. Contrary to his former opinion that 

 the Sphserularia embryos were liberated on the death of their humble- 

 bee host, he now maintains that they find their way into the intestine 

 and are expelled along with the faeces. They were observed abun- 

 dantly not only within the intestine, but in process of passing through 

 the wall. The great mortality among the embryos which he tried to 

 rear is therefore probably to a large extent due to the fact that only 

 those which spontaneously find their way out are able to develope, or 

 to resist the attacks of fungi. 



Prof. A. Schneider has at length been able to bring about arti- 

 ficially the immigration of female Spheerularise into the bumble-bees. 

 Young sexually mature Sphaerularise which had been reared were 

 deposited in damp flower-pots, on which under cover ten queen Bombi 

 were imprisoned. The young Nematodes continued healthy, keeping 

 on the surface of the earth or sand ; in a short time most of them 

 had cast their skins, after which they exhibited a longer and stronger 

 prickle. Most of the queen-bees died from Schizomycetes ; in the 

 sixth four very young Sphserularise were found, all with evaginated 

 uterus, which had in one case about the thickness of the ripe 

 Nematode just before the evagination, and in another one-fourth of 

 the thickness of a Spfiserularia-aheath. in spring. In one of the 

 remaining humble-bees two parasites were again discovered. 



The life-history, according to Schneider, may be thus summarized. 

 The Sphserularia lays eggs in spring, which develope in the body- 

 cavity of the humble-bee. The ripe embryos wander into the in- 

 testine and thence out. They live for five months a free life in the 

 ground, without food and without visible change ; in the middle of 

 September they cast their skins twice, and become differentiated into 

 males and females. They remain a while within the sloughs, but 

 finally freeing themselves, find their way in the middle of October 

 into the queen humble-bees. Immediately after the immigration the 

 uterus is protruded, incorporating the ovary and a coil of the 

 alimentary canal. 



* Tijrlschr. Nederl. Dierk. Vereen., i. (1885) pp. 1-26 (3 pis.), 

 t Zyol. Boitr. (Schneider), i. (1885) pp. 247-51. 



