Botany. '■' 



said that the changes in temperature take place ordinarily 

 v, ,\ Blowly, and this has been found to be a distinct advantage. 



'Hie apparatus can be employed for the examination ol Living 

 plants or microscopic sections, as in both oases the changes oi 

 temperature succeed each other so slowly that one can follow the 

 effects produced by them without any difficulty. G '- L, „ G ; 1 



i '/•/,. disintegration of woody tissues.— A review oi all the 

 processes hitherto published has convinced the writer that the 

 method most widely applicable for the separation oi the structural 

 elements ot hard vegetable tissues, is the following, which has 

 been in use in the Botanical Laboratory of Harvard University 

 for several years. The tissue is soaked for a sufficient length oi 

 time in a ten per cent solution of potassium dichromate, then 

 Quickly freed from the excess of the salt by once rinsing in pure 

 water' ami immediately acted on by concentrated sulphuric acid. 

 Uter'the acid has acted for a short time, the tissue is to be placed 

 in a large quantity of water, when it will he found to have under- 

 gone a more or less complete disintegration, which has left the 

 constituents practically uninjured. When this process, which is 

 really a chromic acid method, is correctly used, there is merely a 

 separation of one structural element from its neighbors, with little 

 or no corrosion of the wall. It has been found easier and far more 

 pleasant to employ than the macerating method m which potas- 

 sium chlorate ami nitric acid are heated together. Moreover, 

 one obtains all the excellent results which can be gained from 

 the most cautious employment of the chlorate method. 



Mr Stone of the Worcester Natural History Society, has shown 

 me that the process is readily applicable to even such tissues as 

 Collenchyma. <T * * ' 



5 Illustrations of West American Oaks, by the late Albert 



Kell , M.D., the text by Edward L. Greene San Francisco, 



1889. 4to, pp. 47.— By an appeal to James M. McDonald, fcsq., 

 of San Francisco, Professor George Davidson secured the funds 

 for the publication of Dr. Albert Kellogg's drawings of the Oaks 

 of California. These excellent illustrations, explained by text by 

 Professor Greene, of the University of California, are now before 

 as and they justify the forcible and discriminating appeal which 

 met with BO prompt a response. The drawings are in outline, 

 with very little shading, and give the chief diagnostic features 

 with much distinctness. That they are truthful in every detail 

 must be believed by all who knew Dr. Kellogg. Ot this enthusi- 

 ast whose drawings of the Oaks are happily saved to us, his 

 friend Professor Davidson says, in the introduction to this work 

 o vi "It was the unselfish and successful work ot Kellogg and 

 his colleages through twenty years that educted the first munin- 

 cent gift of James Lick, and the second still greater one It was 

 his devotion that subsequently elicited the noble gift of Charles 

 Crocker for the endowment of original research . . . As UT. 

 KelkWs vears gradually increased, the held oi investigation 

 BeemeTto expand a hundred fold, and again his singleness ot 



