334 ANNUAL OF SCIENTIFIC DISCOVERY. 



quentl}^ described as distinct species. The chief differences exist 

 in the claspers of the males. The internal sexual organs retain 

 their embr3'onic condition throngh life, even in the largest speci- 

 mens, which may equal the size of the largest fertile individuals. 

 The characteristic spines of the males, upon the upper surface of 

 the pectoral fins, are either wanting or greatly reduced in number 

 in the sterile males. 



Sexes of Spiders.— In the extensive group of Epeiridce, Mr. 

 Pickard Cambridge has never seen an example of the male, and 

 none can be found in the great European museums. They are so 

 very small that they are overlooked by collectors, and resemble 

 horny and spiny ticks. In the large Nepliila, the males are 

 ridiculously small in comparison with the females. This fact 

 illustrates Mr. Darwin's principle of natural selection, as the 

 smaller the male the greater his cliance of escaping the ferocity 

 of the female, by hiding, like a parasite, on various parts of her 

 body ; the point of required safety attained, the males would no 

 longer diminish in size. 



AmpJiioxus. — M. P. Bert, in " Comptes Rendus," corrects some 

 of the errors made by Quatrefages on this lowest form of verte- 

 brates. He denies the existence of the lateral canal opening at 

 the side of the mouth, and describes the position of the abdominal 

 pore and its relation to the body cavity. Like all other fish, 

 amphioxus has the generative glands early developed, and has 

 been seen spontaneously to discharge the spermatic fluid, showing 

 this is not an immature form. He also speaks of the termination 

 of the nerves in corpuscular bodies, as well as a retiform or end- 

 less disposition of the finer nerve twigs. "It seems probable that 

 the corpuscular bodies in connection with nerve-ending and mus- 

 cle fibre may be connected with that form of sensation called the 

 muscular sense, just as other corpuscular bodies (tactile, etc.) are 

 connected with the more obvious perception of heat, cold, etc. 

 The plaques matrices must be regarded merely as corpuscles of 

 muscular sense. — Quart. Journal of Science. 



Pterodactyle. — According to Mr. Seely the pterodact3ie stood at 

 the head of the class of reptiles, and was more highly organized 

 than any other reptile, living or extinct. The characters of the 

 brain were clearly ornithic, and their alleged hollow bone cavities 

 are important facts ; but as no pterosaurian had any sternal rib, 

 their respiration must have difi^'ered from that of birds. 



Ichthyosaurus. — Many have regarded the ichthyosaurus as of 

 an inferior rank, on account of the very great numlDer of bones in 

 the paddle, which represents the hand; but many of the marginal 

 bones, accordhig to Mr. Huxley, have been confounded with the 

 true digits. 



Production of the Sexes of Bees. — M. Landois asserts, as the re- 

 sult of experiments made by himself, that the sex of the bee de- 

 pends on the quality of the nourishment received by the larva in 

 the cell in which the egg was deposited b}- the queen. He states 

 that he has seen eggs deposited in the cells of worker bees give 

 origin to males after having been by him transposed into the cells 

 of males, and vice versa. Experiments by MM. Bessels, Sanson, and 



