1027 



group of plants which no one has hitherto suspected of being parasites, 

 1 mean the sundews, which are hkewise uncultivable. But with re- 

 gard to the species of Drosera there is another anomaly far more 

 singular to be investigated, that of a dicotyledonous plant being 

 parasitical upon a moss, if, as I suspect, the Sphagnum is necessary 

 to the nutrition of the Drosera. There still remains to ascertain the 

 relation of causality between these characters of structure and para- 

 sitism. 



With respect to the peculiar coloration of the blackening juices 

 which these parasitical vegetables contain, that is a question which 

 belongs to chemistry. In conclusion, the foregoing observations 

 upon Melampyrum, Odontites and Alectorolophus explain clearly why 

 it is impossible to cultivate these plants, which do not meet in the 

 artificial soil of our gardens with the roots of those vegetables at 

 whose expense they live ; it also throws some light in ray opinion 

 upon the fact observed by agriculturists, that the Rhinanthacea3 exert 

 an injurious effect upon the grasses and Cerealia. 



Notice of ' An Experimental Inquiry into the cause of the Ascent 

 and Descent of the Sap, with some observations upon the Nutri- 

 tion of Plants ; and the cause of Endosmose and Exosmose. 

 By G. Rainey, M.R.C.S.E., Demonstrator of Anatomy, and 

 of Microscopic Anatomy, St. Thomas's Hospital. London : 

 Pamplin, 1847.' 



Our own observations on this little work will be very brief, and we 

 shall express no opinion as to the value of the theory which Mr. 

 Rainey has broached. The subject is yet in its infancy. Notwith- 

 standing the received and poetic version of the theory of sap, notwith- 

 standing the more precise labours of our microscopists, the reflecting 

 mind cannot but be struck with the paucity of observations and with 

 the poverty of conclusions on a subject which in real interest almost 

 rivals the circulation of the blood. But in inverse ratio to the brevity 

 of our remarks will be the length of our quotations : we wish to place 

 in lucid order before our readers the whole of Mr. Rainey's remarks, 

 claiming for these remarks a patient and attentive investigation, but 

 by no means asserting that we have followed the author through his 

 elaborate researches, or have checked his facts and found his 

 reasoning conclusive. We often observe the man of straw occupying 

 the critic's rostrum and dispensing praise or blame as caprice may 



