240 REVIEWS. 



absorbing their inorganic nutriment on a plan which is nearly uniform 

 ia them all deprive us of another series of valuable characters upon 

 which in the animal kingdom we rely much. Still the nutritive sys- 

 tem of plants displays very important varieties, some of which deserve 

 more minute study than they have yet received, and their reproductive 

 system whilst essentially corresponding with that of the animal king- 

 dom is so wonderfully varied as of itself alone to be almost sufficient 

 for a good system, although we can by no means admit the wisdom of 

 refusing the aid of organs connected with nutrition where we find them 

 affording clear and constant characters, Mr, Clarke finds an analogy 

 between Actiniadse and phanerogamous plants, which if it is any thing 

 beyond the superficial resemblances so often observable in nature must 

 be very vague and general. He thinks indeed that a leaf is a true 

 branch and analogous to the limb of an animal, but assuredly there is 

 no analogy between the branch or limb of a plant and the limb of an 

 animal, the former is the growth of a bud attached to, but in every 

 respect resembling the parent stem and having, like it, leaves specially 

 organized for their peculiar function. In truth if we would see any 

 relation between an animal's limb and a leaf it must be, though then 

 but slight, by carefully distinguishing the leaf from the branch : the 

 inference from the monstrosity of a cabbage leaf is very far fetched 

 and unsatisfactory. Actiniadse belong to a great series of animals 

 made up of a definite number of merosomes each supplied with all the 

 vital organs as if so many separate simple animals had been compressed 

 into complete union round a common axis thus becoming a single in- • 

 dividual, their flower like aspect results from this arrangement. A 

 flower is the reproductive system of a plant, formed by a modification 

 of its leafy organs, which by the suppression of the axis are in that 

 ease brought into successive circles. Is there any more than a super- 

 ficial resemblance, unconnected with structural analogies, between the 

 two ? 



But we have not yet touched upon the really important part of Mr. 

 Clarke's work. We cannot but feel that he has himself given very in- 

 sufficient explanation of his meaning and of the way in which he arrives 

 at his conclusions in respect to the Procarpous and Heterocarpous 

 characters, and we need also to be better informed as to the theoretical 

 grounds on which he rests the importance of these characters. They 

 may be very important and they form a fit subject for investigation. 

 Thus far we chiefly judge of them by their results which by no means 



