BOTANICAL GAZETTE. 139 



Orchids, Polemoniums and Ferns, while it is very rich in Com- 

 posites, Labiates, Pigworts and Solanums." 



Mr. Meehahj in a recent communication to the Philad. Acad. 

 Sci. brought up the question of the manner of entrance of the 

 sporidia oT parasitic fungi. The specimens suggesting the question 

 were the common Panicum sanguinale, or u crab-grass,"which were 

 infested by Ustilago Rabenhdrstiana. Dr. E. Queckett in the 

 Trans. Linn. Soc. had detailed some experiments which seemed to 

 how that the sporidia of the ergot might pass into the circulation 

 of the plant in the water absorbed by the roots. Most unlikely as 

 this seems Mr. Meehan thought his observations looked in the 

 same direction. The Panicum observed was in a field full of indi- 

 viduals and while 50 culms of one plant were infested, the 

 culms interlocking with them and the thousands of others were 

 entirely free; and besides the spikelets were attacked while closely 

 invested by the sheath. All this of course is of the nature of 

 negative proof, but taken with Queckett's experiments may mean 

 something. 



Flora of North America. — In the last Gazette there was 

 published a part of Dr. Gray's address at Montreal upon the above 

 subject. The part selected was that describing his own relation to 

 North American Botany. We give this month that which 

 gives an account of the work upon the^ Flora of North America 

 before the publication of Torrey and Gray's Flora. 



Only two Floras of North America have ever been published 

 as completed works, that of Michaux and that of Pursh. A third 

 was begun (by Dr. Torrey, assisted by a young man who is no 

 longer young) by the publication in the summer of 1838 of a 

 first fasciculus; the first volume of 700 pages was issued two years 

 afterward; and 500 pages of the second volume appeared in 1841 

 and in the early part of 1843. The time for continuing it in the 

 original form has long ago passed by. Its completion in the form 

 in which I have undertaken it anew, is precarious. Precarious in 

 the original sense of the word, for it is certainly to be prayed for: 

 precarious, too, in the current sense of the word as being uncertain ; 

 yet not so, according to an accepted definition, viz: "uncertain, 

 because depending upon the will of another;" for it is not our will 

 but our power that is in question; and it is only by the combined 

 powers and efforts of all of us interested in Botany that the desired 

 end can possibly be attained. 



It were well to consider for a moment how and why it is that 

 a task which has twice been — it would seem — easily accomplished 

 has now become so difficult. 



The earliest North American Flora, that of the elder Mi- 

 chaux. appeared in the year 1803. It was based entirely upon 

 Michaux's own collections and observations, does not contain any 

 plants which he had not himself gathered or seen, is not, therefore, 



