SCIENTIFIC SUMMARY. 
541 
The Chair of Zoology at the Museum of Natural History in Paris, which 
is vacant through the death of M. Valenciennes, the veteran ichthyologist, 
will, it seems likely, he given to M, Lacaze Duthiers, so well known for his 
researches upon Coral and Bivalves, his most formidable opponent being 
M. Louis Eousseau, the assistant naturalist in the Museum. 
The Return of Election of Felloivs of the Royal Society includes the names 
of two most deserving naturalists, whose labours all zoologists will be glad to 
see thus rewarded — Mr. G. K. Gray, known for his contributions to sys- 
tematic zoology, and Mr. W. K. Parker, of whom it is only just to say that 
he is one of the ablest comparative osteologists in Europe. 
A European Axolotl, — M. Dumeril has written to the Academy an- 
nouncing the reproduction of a number of young Mexican axolotls (Siredon 
Mexicanus) in the reptile menagerie of the Natural History Museum. In the 
memoir, or rather note, which the great herpetologist has sent to the Comptes 
Rendus, the development of the ova is minutely detailed, and the evidence 
fully corroborates the long-existing opinion that the axolotl is a true batrachian 
reptile. 
The Circulation of the Blood in Spiders of the genus Lycosa has been care- 
fully investigated by M. Edouard Claparede, who has conducted his inquiries 
chiefly upon the above-named genus, from the circumstance of the trans- 
parency of the individuals it embraces. The heart or dorsal vessel is situate 
in the median line, semicircular in profile, and reniform in transverse section. 
At different parts it presents lateral diverticula, arranged in pairs, of which 
there are three, the posterior one being the least developed. At the level 
of each pair of diverticula there is a pair of those orifices like button-holes 
first discovered by Strauss in insects, and since detected in most of the 
Arihropoda. They are called by M. Claparede “ venous orifices.” At the 
moment of dilatation the blood rushes into the heart by these orifices. There 
are no valves to these orifices in the young LycosEe, their movement depend- 
ing merely on the general muscular fibre of the heart. The blood escapes 
from the heart by the thoracic aorta, and by a tubular posterior or caudal 
aorta ; whence it communicates with a wide reservoir situate at the base of the 
spinnarets. The heart itself is placed in a space which is termed the peri- 
cardial space, whence all the blood entering the heart is derived. M. Clapa- 
r^e considers that the circulation in Lycbsae is par excellence “ lacunar,” and 
regards the “ vascular networks ” of M. Blanchard as having no real existence. 
— Vide The Quarterly Journal of Microscopical Science, No. XVIII. 
The Nervous System of the Earthworm, according to the elaborately con- 
ducted inquiries of Mr. E. Eay Lankester, consists of a supra- and a sub- 
intestinal portion, both of which possess the usual component fibres and 
cells. The principal centre is the cephalic bilobed ganglion, homologous with 
the corpus callosum and the commissure prolonged through the corpora^ quadri- 
gemina (!) From this in one direction pass the cephalic nerves, in the other 
the pharyngeal crura, uniting beneath the pharynx to form the sub-ventral 
cord and ganglia. From the pharyngeal ring four branches on either side 
unite to form the supra-intestinal chain or plexus discovered by Mr. Lockhart 
Clarke, and homologous with the sympathetic and visceral ganglia of mol- 
lusca. Four other twigs on either side are distributed to the pharynx. The 
muscles of the segments are presided over by the sub-ventral cord. There 
