SCIENTIFIC SUMMARY. 
223 
Bombus, which appeared to be B. terrestris , fly to the lowermost flower 
of a spike of this Orchis. It inserted its head into the flower, remaining’ 
about four seconds, and then withdrew it with two pollen-masses attached. 
Ascending from the bottom towards the top, it visited the second and third 
flowers of the same spike. After withdrawing its head from the third 
flower, it stopped a short time and endeavoured to brush off the pollen- 
masses with its legs, but without success. It then continued its visit, 
climbing up the spike, and visited a fourth flower. At this point he tried 
to catch it in the net, but failed, and it flew away. After standing a short 
time they saw a Bombus hortorum visit three or four flowers from base to 
summit of a spike of Orchis mciscula, after which it flew to another indivi- 
dual of the same species, visiting its flowers in the same way. Upon 
examining the stigmas of this second individual, they found pollen scattered 
upon them, and the anther lobes emptied of their pollen-masses. In the 
space of about two hours, which they spent in observing this fecundation of 
Orchis mascula , they noted two visits of Bombus lapidarius and one Psithyrus 
campestris. The Bombus lapidarius did not remain in the flowers longer 
than from two to three seconds. They captured the Psithyrus and one 
Bombus lapidarius. Both had a quantity of pollen-masses upon their heads, 
some of which were already depressed upon their respective stalks, and 
therefore in a condition to rub against and fecundate the stigmas, while 
others were yet erect, and therefore not in a condition to effect fecundation. 
Of ninety-seven bees collected by them in this excursion, thirty-two had 
pollen-masses stuck upon their heads. Sometimes they observed that the 
bees succeeded in freeing themselves from some of the pollen-masses, either 
by tearing them off with their mandibles or brushing them off with their 
fore-legs. Possibly it is in this way that sometimes in the flowers of Orchis 
pollen-masses are found in greater or less proximity to the stigma, out of 
place, and, as it were, wasted. 
Annelids of the Gulf of Naples. — There was published in M. Claparede’s 
name a supplement to his “Ann^lides ch^topodes” of the Gulf of Naples. 
It deals chiefly with the mode of reproduction, and is of especial interest. 
Malmgren in 1864 was first led to suspect a genetic relation between 
Nereis and Heteronereis, from a comparison of Nereis pelasgica and 
Heteronereis grandifolia , showing nearly an absolute identity, with the 
exception of the peculiar foliaceous appendages and bristles of the posterior 
part and other minor characters only developed at the period of sexual 
maturity. This led him to look upon certain species of Nereis as the 
agamous stock of sexual individuals appearing as Heteronereis. Subse- 
quently having found eggs in this presumed agamous Heteronereis stock, 
he came to the conclusion that, although all the species of Iphinereis and 
Heteronereis were only sexual forms in series of generations still unknown, 
yet that, at some time during sexual maturity, a stage of one of the poly- 
morphous species of Nereis assumes the characters of Heteronereis, to lose 
them subsequently and return to its agamous stage. Malmgren accounted 
for the genetic relations by an alternate generation at first, and afterwards by 
a metamorphosis ; both of which hypotheses Claparede shows conclusively 
are justifiable. Ehlers has shown that a large number of species of Hetero- 
nereis were only sexual forms of previously known species of Nereis, and 
