114: PROCEEDINGS OF THE ACADEMY OP 



the highest animal. In our opinion it may be demonstrable, that the first 

 assumption of life manifests itself in objects constituting a primary great 

 class or kingdom of more simple organization than either the animal or vege- 

 table kingdom, and possessing also an equally characteristic specialization in 

 its structure and functions. 



The consideration of the question of determinable characters on the assump- 

 tion of the existence of two primary divisions or kingdoms only may now 

 safely be regarded as exhausted, without conclusive result or an approxima- 

 tion to such, sufficient even to obtain general adoption temporarily as a pro- 

 bable antecedent hypothesis, awaiting demonstration. Much has been at- 

 tempted and numerous propositions and theoretical definitions have been 

 thoroughly canvassed, to the end only of showing their insufficiency. Volun- 

 tary motion and permanent fixedness, the presence or absence of nitrogen, 

 internal or external stimuli, the differences in the method and substances of 

 nutrition, and many other problems have, in their attempted solution, failed 

 to give the desired formula, and there are those who may be presumed to be 

 well acquainted with all the researches touching questions here alluded to, 

 who infer summarily that there is no difference radically, or in the lowest 

 forms of organization in the two kingdoms Animalia and Vegetabilia, as al- 

 most universally supposed to be constituted. As an example, we cite the 

 distinguished botanist Professor Lindley, of London, who says, in the Intro- 

 duction to his standard and well known work on the Natural System of Bo- 

 tany, " Plants are not separable from animals by any absolute character, the 

 simplest individuals of either kingdom not being distinguishable by our 

 senses," (p. 15, New York, 1S31). Of a somewhat similar tenor, but with 

 an implication more in accordance with our views on this hitherto intricate 

 subject, is an observation by Professor Owen, of the British Museum : " No- 

 thing seems easier than to distinguish a plant from an animal, and in common 

 practice, as regards the more obvious members of both kingdoms, no distinc- 

 tion is easier ; yet, as the knowledge of their nature has advanced, the diffi- 

 culty of defining them has increased, and seems now to be insuperable." 

 (Hunterian Lectures, p. 2, London, 1855.) 



Inthe higher developments of the animal and vegetable kingdoms there is 

 truly the utmost possible readiness of distinction, and this great facility seems 

 to have led to an inference that the same readiness and facility ought to pre- 

 vail throughout the two supposed kingdoms. "At first sight," says Professor 

 Van der Hoeven, "it seems easy to distinguish an animal from a plant, and 

 even the most unskilled person thinks he has a clear notion of the difference. 

 Yet it is just his want of knowledge that causes the difference to appear so 

 prominent, whilst he overlooks the intermediate links, and thinks, for in- 

 stance, of a dog and a pear tree," (Handbook of Zoology, i. p. 4, Cambridge, 

 1856). We do by no means admit, however, that the principle here implied 

 and apparently involved, which seems to be that the higher groups of any 

 grade, whether kingdoms or other, are more easily recognizable and definable 

 than the lower, is correct. The truth is, very probably, that the lower forms 

 in all groups, are, at least, as readily to be assigned to their proper positions 

 in the natural system as the higher ; possibly more so, in some instances. 

 In the two kingdoms, Animalia and Vegetabilia, there is no difficulty with 

 forms properly belonging to either of them, and of either high or low grade 

 of development. The difficulty and, in fact, impossibility hitherto has 

 been with organizations inferior to both, and properly belonging to neither. 

 Though in an early zoological epoch the corals and other groups may have 

 been regarded as of doubtful status, there is at present no group in either the 

 animal or vegetable kingdom, rightly defined, which, in our opinion, presents 

 any doubt or difficulty in its being assigned to either one or the other, and, 

 probably, very generally, nearly correctly according to its actual or relative 

 rharacters and its affinities. 



[May, 



