OF LIFE, AND ITS CONDITIONS. 27 



ascertain the conditions on which the activity of each of these is dependent, 

 before we can rightly comprehend their united action in the Lii'e of the 

 whole. No fact has been more clearly ascertained by modern Physiological 

 research than this, that as the germ derives from its parent certain inde- 

 pendent endowments, in virtue of which it is enabled to develop itself 

 (under appropriate conditions) into an organism which may be composed 

 of a vast number of dissimilar parts, so each of those parts derives from 

 the germ in which it had its origin an independent capacity for develop- 

 ment and maintenance, in virtue of which it goes through its own course 

 of vital activity, and by the ultimate cessation of which its own term of 

 existence is limited. Of this mutual independence we have illustrations 

 in the persistence of the "molecular life" of individual parts long after 

 "somatic" death (or death of the body as a whole) has taken place; in 

 the fact that not only may vital activity be sustained in a part completely 

 separated from the body by the maintenance of the circulation of blood 

 through it, but vital endowments which had partially or completely ceased 

 to manifest themselves in consequence of the cessation of the circulation, 

 may be restored by its re-establishment; and in the occasional reunion of 

 members which have been entirely separated. But notwithstanding the 

 wonderful diversity of structure and of endowments which w T e meet with in 

 the study of any such complex organism, we encounter a harmonious unity 

 or co-ordination in its entire aggregate of actions, which is yet more won- 

 derful. It is in this harmony of co-ordination, whose tendency is to the 

 conservation of the organism, that the state of Health or Normal Life es- 

 sentially consists. And the more profound is our investigation of its con- 

 ditions, the more definite becomes the conclusion to which we are led by 

 the study of them, that it is fundamentally based on the common origin of 

 all these diversified parts in the same germ; the vital endowments of which, 

 equally diffused throughout the whole fabric in those lowest forms of 

 organization in which every part is but a repetition of every other, are 

 differentiated in the highest amongst a variety of organs or instrumental 

 structures more or less dissimilar, acquiring in virtue of this differentiation 

 a much greater intensity. 



5. In the lowest forms of Vegetable life, the primordial germ multiplies 

 itself by duplicative subdivision into an apparently unlimited number of 

 cells, each of them similar to every other, and capable of maintaining its 

 existence independently of them. And in that lowest (Rhizopod) type of 

 Animal life, the knowledge of which is among the most remarkable fruits 

 of modern biological research, " the Physiologist has a case in which those 

 vital operations which he is elsewhere accustomed to see carried on by an 

 elaborate apparatus, are performed without any special instruments what- 

 ever ; a little particle of apparently homogeneous jelly changing itself into 

 a greater variety of forms than the fabled Proteus, laying hold of its food 

 without members, swallowing it without a mouth, digesting it without a 

 stomach, appropriating its nutritious material without absorbent vessels or 

 a circulating system, moving from place to place without muscles, feeling 

 (if it has any power to do so) without nerves, propagating itself without 

 genital apparatus, and not only this, but in many instances forming shelly 

 coverings of a symmetry and complexity not surpassed by those of any tes- 

 taceous animals;" L whilst the mere separation of a fragment of this jelly 

 is sufficient to originate a new and independent organism, so that any 

 number of these beings may be produced by the successive detachment of 



1 See the Author's Introduction to the Study of the Foraminifera, published by 

 the Ray Society, 18G2, Preface, p. vii. 



