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But the principle of reversion, by which a long-lost structure is called back into existence, might serve as the guide for its full development, even after the lapse of an enormous interval of time. Professor Canestrini, after discussing the foregoing and various analogous cases, arrives at the same conclusion as that just given. 'Annuario della Soc. dei Naturalisti, Modena, 1867, p. 83. Prof.
Spiders are possessed of acute senses, and exhibit much intelligence; as is well known, the females often shew the strongest affection for their eggs, which they carry about enveloped in a silken web. The males search eagerly for the females, and have been seen by Canestrini and others to fight for possession of them.
Hence Canestrini concludes that some ancient progenitor of man must have had this bone normally divided into two portions, which afterwards became fused together. In man the frontal bone consists of a single piece, but in the embryo, and in children, and in almost all the lower mammals, it consists of two pieces separated by a distinct suture.
Canestrini gives extracts on this subject from various authorities. Laurillard remarks, that as he has found a complete similarity in the form, proportions, and connection of the two malar bones in several human subjects and in certain apes, he cannot consider this disposition of the parts as simply accidental. Another paper on this same anomaly has been published by Dr.
The extrinsic muscles which serve to move the external ear, and the intrinsic muscles which move the different parts, are in a rudimentary condition in man, and they all belong to the system of the panniculus; they are also variable in development, or at least in function. Canestrini quotes Hyrtl.
Birds when surrounded by caterpillars would probably devour the largest; and Professor Canestrini informs me that in Italy some breeders believe, though on insufficient evidence, that in the first broods of the Ailanthus silk-moth, the wasps destroy a larger number of the female than of the male caterpillars. Dr.
Siebold, C.T., von, on the proportion of sexes in the Apus; on the auditory apparatus of the stridulent Orthoptera. Sight, inheritance of long and short. Signal-cries of monkeys. Silk-moth, proportion of the sexes in; Ailanthus, Prof. Canestrini, on the destruction of its larvae by wasps; difference of size of the male and female cocoons of the; pairing of the.
Canestrini draws the same conclusion from the fact that the males of certain species present two forms, differing from each other in the size and length of their jaws; and this reminds us of the above cases of dimorphic crustaceans. Aug. In this species, as I may add, the male is testaceous and the female black with legs banded with red.
This suture occasionally persists more or less distinctly in man after maturity; and more frequently in ancient than in recent crania, especially, as Canestrini has observed, in those exhumed from the Drift, and belonging to the brachycephalic type. Here again he comes to the same conclusion as in the analogous case of the malar bones.
Canestrini, G., on rudimentary characters and the origin of man; on rudimentary characters; on the movement of the ear in man; of the variability of the vermiform appendage in man; on the abnormal division of the malar bone in man; on abnormal conditions of the human uterus; on the persistence of the frontal suture in man; on the proportion of the sexes in silk-moths; secondary sexual characters of spiders.
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