I 

 INDUSTRIAL PROGRESS DURING THE YEAR 1873. ciii 



Duthiers' Archives (April, 18V3) ; while Gervais' Journal de 

 Zoologie contains an abstract of the Italian anatomist's (Dr. 

 Leone de Sanctis) paper on the embryonic development of 

 the electrical organs of the Torpedo. He finds that they 

 are developed from the "middle" embryonic layer of cells 

 of embryologists. They arise from the subcutaneous con- 

 nective tissue. Tliis median layer furnishes the abundant 

 nervous tissue of the peripheral nerves, which forms the es- 

 sential part of the organ. 



A number of launal lists and notes on the habits o^ JBirds 

 have appeared in the American Naturalist^ and the valuable 

 work of Dr. E. Coues, entitled "A Key to the Birds of North 

 America," will for a long time to come remain the most com- 

 pact manual of American ornithology that the student can 



procure. 



BOTANY. 



In the field of Botany the English systematic botanists 

 have been especially busy. The most important of their 

 w^orks has been a continuation of the " Genera Plantarum," 

 by Bentham and Hooker (devoted mainly to the large and 

 difticult orders Ruhiacem and Compositce)^ and the cognate 

 article upon the classification, history, and geographical dis- 

 tribution of the latter order, by Mr. George Bentham, in the 

 Journal of the Linnsean Society. The elaboration of the 

 Riibiacece was done by Dr. J. D. Hooker, that of the Com- 

 positce by Mr. Bentham, who has followed a system of classi- 

 fication diflTering widely in some respects from that of De 

 Candolle and other botanists, with a large reduction in the 

 number of genera. In his later article, he explains at length 

 the principles of the arrangement adopted by him, discusses 

 the relative value of the characters that have been relied 

 upon for distinguishing tribes and genera, and considers the 

 conjectural history of the order, as deducible from its pres- 

 ent geographical distribution, which is given with full detail. 

 Several of the new genera and species of the " Genera Plan- 

 tarum" are illustrated by Dr. Hooker in an issue of his 

 " Icones Plantarum." 



Mr. Bentham's anniversary address as president of theLin- 

 naean Society was, like his previous ones, a production of 

 great interest and value, and is occupied in large part by the 

 question of the gymnospermy of conifers and their allies, 



