MODES OF ORIGIN COMPARED 59 



our hypothesis, the Bacterium and the Torula corpuscle are only 

 different modes of growth which may be assumed by new-born 

 specks of living matter ; so also, as might be expected, are the 

 varieties of each kind of growth both numerous and transitional. 

 We have seen that each of the forms, under suitable conditions, 

 may grow in a continuous rather than in a discontinuous fashion, 

 the Torula then producing variously branched and articulated 

 hyphje, which at intervals are apt again to revert to the discon- 

 tinuous mode of growth, so as to produce ' reproductive units ' — 

 either in single file as buds from a terminal expansion, or by 

 segmentation of the contents of a terminal chamber. These, and 

 many other simple variations in the mode of production of the 

 reproductive units, variously combined with different sizes, modes 

 of branching, articulation and segmentation of the filaments, go to 

 produce the innumerable simpler kinds of Fungi or ' Moulds' which, 

 like the innumerable varieties of Bacteria, instead of being lineal 

 descendants of similar mutable organisms that lived in a pre- 

 Adamite world, may be only different modes of growth continually 

 being assumed by new-born living matter. 



What is to be observed concerning the mutability of these low 

 forms of hfe may, therefore, fairly be said to be quite consistent 

 with the notion that they are, as they seem to be, capable of arising 

 de novo in suitable fluids. 



And if true, this would again be quite in harmony with what we 

 have attempted to show in the previous chapters. We have seen 

 how, under the influence of the well-established doctrine con- 

 cerning the Persistence of Force — and more especially since the 

 clear recognition of the subordinate doctrine as to the correlation 

 existing between Physical and Vital Forces — the majority of bio- 

 logists have long recognised that the phenomena manifested by 

 living beings are to be ascribed simply to the properties of the 

 matter as it exists in such living things. No one has expressed 

 himself more decidedly on this subject than Prof. Huxley, and he 

 may fairly be taken as an exponent of the modern doctrines on this 

 question. In a striking article on " The Physical Basis of Life " 

 he said ^ : — " But it will be observed that the existence of the 

 matter of life depends on the pre-existence of certain compounds, 

 namely, carbonic acid, water, and ammonia. Withdraw any one of 

 these three from the world and all vital phenomena come to an end. 



' " Fortnightly Review," Feby. 1869, p. 129. 



