LIUiS'B.VN' SOCIETT OF LONDON". IxiX 



diversity of tho atoms ; tkat both are equally affected by chemical 

 agents, and especially by carbonic combinations ; only, he after- 

 wards adds, these carbonic combinations are much more complicated 

 in organized than in inorganic bodies. But is not this very com- 

 plication, by which the ordinary action of physical or chemical 

 agents is checked or modified, one of the great and constant dif- 

 ferences between the living and the inorganic body ? 



Ilcjccting, then, all distinctions derived from morphology or che- 

 mical action, Haeckcl rests the definition of Organisms upon purely 

 physiological grounds, giving it the following form : — " We call 

 Organisms all those natural bodies which exhibit the peculiar active 

 phenomena (Bewegungserscheinungen) of life, and especially the 

 universal one of nutriment " — an excellent definition as far as it 

 goes, and aU we could wish for, but that he adds, in a note, " The 

 three functions of nutrition, growth, and reproduction (Eortpfian- 

 zung) are commonly designated as the general active phenomena 

 attributable to all organisms ; we have not here adduced growth^ 

 because it occurs equally in inorganic individuals ; nor reproduction, 

 because it is wanting in many (asexual) organic individuals." He 

 must, however, be aware that when growth is attributed to living 

 and denied to inorganic bodies, what is meant is not growth in that 

 comprehensive sense given to the word by Linnceus in the oft-quoted 

 definition of " Lapides crescunt, &c.," but growth by intussusception 

 and assimilation, as distinguished from external aggregation — a con- 

 trast well worked out, as characterizing the two great classes, by 

 Uaeckel himself (vol. i. p. 141 et seq.), — and that reproduction in- 

 cludes asexual as well as sexual reproduction. 



With the above definition of an Organism, the whole of the argu- 

 ments by which he attempts to show that there is a wider gap 

 separating his Moneres from other organic bodies than from inor- 

 ganic ones appear to me to fail, or to rest solely on the supposed 

 absolute simplicity of these organisms. But the only evidence in 

 favour of this simplicity and homogeneity is the negative one that 

 our instruments can detect no internal structure, whilst the only 

 positive o!ie, the facts of their nutrition, division, development, and 

 alterations of form, as in the Protogenes and Protamoeba above 

 alluded to, tells in the contrary direction. 



- As to the question of the autogony, spontaneous generation, or 

 original formation of simple organisms out of inorganic matter, and 

 the comparison between the formation of a primordial cell and an 

 elementary crystal, notAvitlistanding the ingenuity of some of his 



