SCIENTIFIC SUMMARY. 
109 
this place in 1802. Bats are numerous in the avenues within a mile or two 
of the mouth of the cave, and Mr. Mansell thinks he has secured at least 
two species. 
The Species of Coitus Grcenlandieus. — Dr. Gill has lately communicated 
to the Academy of the Natural Sciences of Philadelphia a paper of some 
importance on the apparently different forms of the species. Descriptions 
in several works have been based on only one of these forms, but in 
Giinther’s “Catalogue of the Acanthopterygian Fishes ” (II. p. 161), under 
the general term Coitus GrtBulanclicus, the two forms are mentioned, one 
being, “Var. a. Sides of the belly with large white spots j’’ the other, 
“ Yar, Sides irregularly marbled ; ” each was represented in the British 
Museum by four specimens. No suspicion of any sexual relation of those 
forms was expressed. The universal occurrence of these two forms 
together and in approximately equal numbers led Dr. Gill to suspect that 
they really represented sexual conditions of the same species. Dissection 
confirmed the suspicion, and it was found that all individuals with white 
spots on the abdomen were males, and all without females. 
The Fertilization of the Yucca Plant. — Professor C. V. Riley, of St. Louis, 
U.S., has lately discovered that the fertilization in this plant is performed 
by a small white moth which he calls pronuba Yuccasella, and which forms 
the type of a new genus. It is most anomalous from the fact that the female 
only has the basal joint of the maxillary palpus wonderfully modified into a 
long prehensile spined tentacle. With this tentacle she collects the pollen 
and thrusts it into the stigmatic tube, and after having thus fertilized the 
flowers she consigns a few eggs to the young fruit, the seeds of which her 
larvae feed upon. The Yucca is the only entomophilous plant known which 
absolutely depends for fertilization on a single species of insect, and that 
insect is remarkably modified for the purpose. The plant and its fructifier 
are inseparable under natural conditions, and the latter occurs throughout 
the native home of the former. In the more northern portions of the United 
States, and in Europe, where our Yuccas have been introduced and are 
cultivated for their showy blossoms, the insect does not exist, and conse- 
quently the Yuccas never produce seed there. The larva of the pronuba 
eats through the Yucca capsule in which it fed, enters the ground and hiber- 
nates there in an oval silken cocoon. In this stage the insect may be sent 
by mail to this country, and our English botanists may, by introducing it, 
soon have the American Yucca produce seed without any personal effort. 
The Thread Hilaria Anhinya Worm in Brain of Snake Bird. — Mr. J, 
Wyman states that during last winter he had the opportunity of examining 
ten of these birds, in addition to those of which he speaks in a report to the 
Boston Society of Natural History in 1868. He says that the proportion of 
the infected ones was less than in the previous examinations, no worms 
being found in four. Two of these were not mature birds, but of the age of 
the other two he has no record. Of the six in which worms were found 
four had both male and female Filarise, while two had only females, viz. 
one had one and the other three In the instances where both sexes were 
present, the eggs were found, as before, in various stages of development, 
bile in the others, where females only existed, the oviducts were full of 
e 2 -[^s and in the same numbers as in the others, but there were no signs of 
