18 REPORT — 1855. 



the surface of which was a little water; it was placed in the garden with a 

 sunny aspect. Mould was introduced, and some seeds of wheat and peas. 

 After fourteen days it was found that the peas had merely split, and were 

 black and decomposed, while the wheat showed no signs of germination, and 

 were quite soft and decayed. An analogous experiment was made with pure 

 oxygen gas. Both the peas and wheat germinated and grew a little, until no 

 doubt the atmosphere of the jar was in a great measure converted into car- 

 bonic acid, when they also decayed. It appears then that carbonic acid in 

 considerable excess has a positively injurious effect on germination. 



In concluding the record of this investigation of the influence of solar ra- 

 diations on the growth of plants under different atmospheric conditions, I 

 feel very sensible of the imperfect nature of the results, and am convinced 

 that such are the difficulties of the inquiry, that the conclusions actually 

 arrived at must not be generalized without the greatest caution. Yet at the 

 same time I beg to express the hope that other observers may take up some 

 of the questions, to which I have incidentally alluded, but which still remain 

 unanswered. 



On the British Edriophthalma. By C. Spence Bate, F.L.S. ^c. 



Part I. — The Amphipoda. 



Introduction. — The term Edriophthalma has been given by Dr. Leach and 

 recognized by all subsequent naturalists, as applied to a legion of Crustacea 

 that differs in several of its external characters, independently of the eyes, 

 from that on which he has conferred the antagonistic term oi Podophthalma. 



These two applications are not capable of comprehending within their 

 separate significations every genus which it is desirable should be so 

 embraced. There is a whole family that belongs to the Macroural type, 

 the eyes of which are sessile, being lodged beneath the integument of the 

 antennal segments. This infringement, which occurs in the Diastylidm *, 

 shows us that it is not necessarily a law among Crustacea that the eyes shall 

 be borne on footstalks whenever there is a tendency to an accumulation of 

 the nervous ganglia into a central mass, even though that centralization be 

 more or less imperfect. 



Again, the infringement is repeated upon opposite evidence, for we per- 

 ceive that the eyes may be borne on footstalks where the nervous system is 

 divided into many separate ganglia. The genus Tanais among Jsopoda has 

 the eyes raised upon distinct pedicles, which we believe are moveable, and 

 differ from the eyes of the Podophthabna only in being less club-shaped. 



But ever since the time of the great Swedish naturalist, Linnaeus, the rela- 

 tive position of the eyes has been held as a means of natural classification, 

 distinctly separating one great family of Crustaceans from that of another ; 

 and although there are exceptions which demonstrate that the arrangement 

 is not free from error, yet so very generally is the aiiplication correct and so 

 easily capable of discernment, that it probably will remain a permanent 

 mode, even should a more perfect but less readily detective system of natural 

 arrangement be discovered. 



The term Edriophthalma was first understood to contain all the Crustacea 

 which were not embraced within that of Podophthabna, and, with the excep- 

 tion of the Cirripedia, they are still so retained in Mr. Dana's classification of 

 * Cuma, &c. of M. Milne-Edwards. 





