532 



NA TURE 



[Oct. 31, 187: 



necting link between flowering and flowerless plants. 

 It seems to us a mistake to attempt in an introductory 



f r^ 



.^^ 



V 



Fig. 3.— Prothallium o{ Scolo/'CitdriHm, with Anlheridia (magnified) 



text-book even an outline of the characters of the natural 

 orders of flowering plants ;' but if this were necessary to 





Fig. 4.— ror<:nofPiollialliumof/'/.-r 

 ami Archego 



■ulattt, showing Anthcriji. 



the plan, this portion should have been completely 

 re-arranged, to make it conform to the present state of 



botanical science. The chief advantage of the systematic 

 portion of a course of botanical lectures is tliat it gives 

 the teacher the opportunity of demonstrating the value in 



classification of certain peculiarities of structiircjjy placing 

 side by side species belonging to the same and to allied 

 natural orders, in a manner better calculated to arrest the 



attention of the student than if presented to him in any 

 other way. This advantage, however, is not gained by 

 the introduction of a section devoted to the details of 

 classification into a text-book. 



-)H 



Fn.. 7.— Isuhitcd Archego 1 n I inc ihe ictiun of the Anthcro/oiiU 

 upon the Embrjonal Cell 



The fourth part of the work, on the " Geographical 

 Distribution of Plants," though too brief, is interesting, 

 and contains much valuable information in a small 

 space. 



Altogether, this English version of Figuier's "Vegetable 

 World" is a good book to place in the hands of an in- 

 telligent student who is desirous of learning something of 

 the laws which govern plant life. A. W. B. 



LETTERS TO THE EDITOR 



\The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. No notice is taken of anonymous 

 communications. ] 



Ocean Currents 

 If Mr. Laughton will take the trouble to read my previous 

 Reports with attention, he will find that 1 have based no atgiiin,nt 

 upon my " trough " experiment, which I have used merely as an 

 illustration. The argument in favour of the vertical Oceanic Cir- 

 culation which I advocate rests upon ihi facts of Deep Sea Tem- 



