ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
seen in the llexapoda is explained by referring them back to the 
acicular glands of vanished dorsal parapodia. Specialization of parts 
of the body explains the incompleteness of the metameric arrangement 
in the adult Hexapod. 
The only difficulty seen by the author is to be found in the 
arrangements exhibited by the Arachnida, for they possess coxal 
glands, with which apparently there is nothing to correspond in the 
Hexapoda. It is urged, however, that these glands may be left out of 
consideration without seriously affecting the derivation of tracheae from 
setiparous glands ; if, however, it can be shown that the coxal glands 
of the Arachnida are developments of Annelidan acicular or setiparous 
glands the arguments used in the present paper would be considerably 
strengthened. 
a. Insecta. 
Development of Melolontha vulgaris.* — M. Y. Raspail has some 
notes on the development of M. vulgaris , which like many Coleoptera, 
has a very long larval life ; it is remarkable, however, that the length of 
this larval life may be three years or four. This difference has been 
erroneously attributed to differences in temperature and food ; the 
author finds that it is really due to differences in humidity, for a genera- 
tion of four years has been found to correspond with a series of dry 
seasons, and the three-year form to two damp years. 
Structure and Life-history of Encyrtus fusicollis. f — Prof E. 
Bugnion gives an account of this small hymenopterous parasite. The 
eggs are laid in the second half of May when the larvae of Hyponomeuta 
(the host) are about a centimetre in length. By one puncture the female 
introduces a chain of 50-120 ova into the perivisceral cavity. Some- 
times the same larva is punctured by two or three individuals. The 
membranous tube enclosing the embryos seems to be a cuticular forma- 
tion of an internal epithelium which is derived from the fusion of the 
amniotic or serous envelopes of the embryos. The granular substance 
surrounding the embryos within the tube is probably vitelline, but it 
increases by osmosis from the lymph of the host. It nourishes the 
larvae until the 20th to 25th June, when they moult, rupture the tube, 
and begin to feed directly upon the lymph of their host. As the time 
of metamorphosis approaches, the larvae devour the viscera, and each 
becomes about the 7th July encapsuled in a chamber. The host dries 
up; the nymph period lasts about three weeks; the hatching occurs 
from 27th July to 2nd August. In one host the parasites are generally 
either male or female, the former probably the result of parthenogenetic 
development, the latter of early fertilization. Pairing occurs im- 
mediately after liberation and seems to last only for a few seconds. 
* Bull. Soc. Zool. France, xvi. (1891) pp. 271-5. 
f Bee. Zool. Suisse, v. (1890) pp. 435-70 (2 pis.), and 1892, pp. 471-534 (4 pis.). 
This final part of the ‘ Recueil Zoologique Suisse ’ (October 1892) contains the sad 
announcement, “ Le 13 mars 1892, M. le Professeur Hermann Fol, directeur du 
Bee. Zool. Suisse, s’embarquait au Havre, h bord du yacht V Aster arme en vue d’une 
campagne scientifique. . . . Plusieurs mois se sont ecoules depuis son depart et l’on 
est encore sans nouvelles du yacht et de ses passagers. Les recherches entreprises 
par le Ministere de l’lnstruction publique et par la famille de M. Fol sont restees 
infructueuses.” 
1893. 
D 
