*298 BOTANICAL GAZETTE. 



oplasts occur of all shades from carmine-red to greenish-yellow, but never blue. 

 And so with chlorophyll corpuscles, pigment bodies, starch-formers and sundry 

 other substances closely related, we may hope that we are apjiroaching a 

 natural classification of oell contents. — J. M. C. 



The Genera Plantarum. — In the September Am. Jour. Sci. Dr. Gray re- 

 prints from the Nation a notice of the completion of Bentham and Hooker's 

 Genera Plantarum. Begun in 1862 and finished this year, it stands as the second 

 great botanical work of the century, the " Prodromus " of De Candolle being 

 the other. Dr. Gray compares the various " Genera Plantarum " which have 

 been published in the following interesting way : 



" Some idea of the progressive enlargement of the field may be had by a 

 comparison of the number of genera characterized in these successive works. 

 The pha j nogamous genera of 



Linnaeus, " Gen. PL," ed. 1, A. D. 1737, were 887 



ed. 6, A. D. 1764, " 1189 



Jussieu, " A. D. 1789, " 1707 



Endlicher, " A. D. 1843, " (about) 6400 



Bentham & Hooker, A. D. 1883, " 7585 



If the last had been elaborated upon the scale of Endlicher, or with the 

 idea of genera which is still common if not prevalent, the number of genera 

 would have amounted to at least ten thousand. An estimate of the number of 

 known species of each genus and higher group h.as been made throughout the 

 work — a rough approximation only, mentioning first the number in the books, 

 and the number to which, in the opinion of the authors, these may probably 

 be reduced by the botanists who adhere to the Linnsean view of species ; from 

 which it appears that, upon the very strictest estimate, their number, as now 

 known to botanists, is at least 95,620. In round numbers, it may fairly be said 

 that about 100,000 species of phamogamous plants are in the hands of botanists. 

 The five largest orders, as well for genera as for species, are the following, and 

 in this rank : Composita', Leguminosa^, Orchideae. Rubiaceae, Gramineae. The 

 high standing of the orchid family in the list will be a surprise to many. Lin- 

 naeus knew only a hundred species ; five thousand is now a moderate estimate 

 — about half as many as there are of Composite, which hold to their propor- 

 tion of one-tenth of the whole. In both families every country and district is 

 largely peculiar in its species and types. The far greater prominence of Com- 

 posite over orchids is owing to the vast number of individuals in the former, 

 and their paucity in the latter." 



Injurious Parasitic Plants.— It has become the fashion in certain quar- 

 ters to decry the work done by the Department of Agriculture, but this is by 

 no means politic or kind. The department is blessed with a maximum amount 

 of ambition and a minimum amount of money, and it is hard to see how it 

 could do more. Much good work has already been done, work that has yielded 

 abundant returns in the better cultivation and preservation of various crops. 

 (.'. V. Riley, in charge of the Entomological Commission, has well investigated 

 the haunts and habits of various noxious insects, and the cost of these investi- 

 gations has been but a trifle when compared with the damage to crops that ha> 



