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reference to them. It appeared that they had been recently found in 
alluvial deposits in that island under three feet of water and mud, after 
unsuccessful researches in drier localities, and that bones of the tortoise, 
deer, and flamingo, were discovered at the same time and place. Nearly 
every bone of this remarkable bird had been obtained there, except the 
toes and part of the beak. The skull was very thick, and the cerebral 
cavity small ; the cervical vertebrae were especially worthy of attention, 
the spinal cord being fully double that of a turkey in size ; the sternum 
resembled that of the pigeon tribe, and the leg bones were remarkable for 
their size, some of the femurs being 7 inches in length. 
Mr. A. LEiPNERthen made a communication upon "Asexual Reproduc- 
tion." The speaker had been led to consider the subject, by reading some 
recent researches of Leuckart on the Cecidomyde larvae, a race of two- 
winged flies, which, depositing their eggs in the buds of plants, produced 
galls. Between the 9th and 10th segments of the larva appeared a ' germ- 
stock,' which, after going through several stages, finally developed into a 
number of larvae, precisely resembling the original one, which ate their 
way out of the parent's body, causing its death. These again produced 
others, and so on, until June, when the larvae went through the usual 
metamorphoses, and the resulting insects, after copulation, laid eggs, 
which developed in the usual manner. The only parallel condition to this 
was in the Aphides, or plant-lice, where this successive production of larvae 
without sexual organs had been continued for four years, but any great 
fall in the temperature caused a full development of the larvae, followed 
by sexual reproduction, to take place., Leuckart had adopted Steenstrup's 
term for this phenomenon, ' alternation of generations.' In his treatise 
on Development, M. Quatrefages described three modes. (1.) True 
Metamorphosis, which affected only one and the same individual. (2.) 
Geneagenesis, or the production of several generations through the 
medium of a single germ, and (3.) Parthenogenesis, or the reproduction 
of perfect eggs from an unfecundated perfect female ; as had been long 
noticed among bees, and as frequently occurring in the vegetable kingdom. 
Mr. Leipner considered the reproduction of the Aphides and Cecidomydae 
as coming under the second head, geneagenesis, as no perfect eggs were 
produced, nor was the reproducing individual a perfect insect ; the process, 
in fact, was only a modification of the phenomenon of gemmation or 
budding, examples of which he adduced from among many of the lower 
tribes, Coelenterata, Radiata, Annulosa, Mollusca, &c. The speaker 
hoped at a future time to present a classification of animals founded upon 
their modes of reproduction, according to the divisions laid down by 
Quatrefages. 
