258 ANNUAL OF SCIENTIFIC DISCOVERY. 



accepted it as a provisional term. What he wished to point out was, 

 that in the sense in which it was employed by Dr. Daubeny, it was 

 only equivalent, as Dr. Jepen had stated, to the u crystallizing force" of 

 minerals, which exercised the same selecting power in crystallizing as 

 the roots of plants did in growing. The only phenomena in plants 

 for which we had really no physical explanation were, the movements 

 of the protoplasm in the interior of the cells of plants, and the locomo- 

 tive power of unicellular plants and their cilia. These movements 

 were similar to the muscular contractility and nervous sensibility of the 

 hiffhest animals. These movements were, however, dependent on phys- 

 ical causes, and the chemical decomposition of the sugar and protein 

 of our food was necessary for their development. As to death's not oc- 

 curring in the mineral world, this was but another name in animals 

 and plants for change ; and change occurred in crystals and in all 

 the physical phenomena of the universe, as much as in organic bodies. 



PHYSIOLOGY OF REPRODUCTION. 



The student of nature wonders the more, and is astonished the less, 

 the more conversant he becomes with her operations ; but of all the 

 perennial miracles she offers to his inspection, perhaps the most worthy 

 of admiration is the development of a plant or an animal from its em- 

 bryo. Examine the recently laid egg of some animal, such as a sala- 

 mander or a newt. It is a minute spheroid in which the best micro- 

 scope will reveal nothing but a structureless sac, enclosing a glairy 

 fluid, holding granules in suspension. But strange possibilities lie dor- 

 mant in that semi-fluid globule. Let a moderate supply of warmth 

 reach its watery cradle, and the plastic matter undergoes changes so 

 steady and purpose-like in their succession, that one can only compare 

 them to those operated by a skilful modeller upon a formless lump of 

 clay. As with an invisible trowel, the mass is divided and subdivided 

 into smaller and smaller portions until it is reduced to an aggrega- 

 tion of granules not too large to build withal the finest fabrics of the 

 nascent organism. And, then, it is as if a delicate finger traced out 



t? C2 



the line, to be occupied by the spinal column, and moulded the contour 

 of the body ; pinching up the head at one end, the tail at the other, 

 and fashioning flank and limb into due salamandrine proportions, in so 

 artistic a way that, after watching the process hour by hour, one is al- 

 most involuntarily possessed by the notion that some more subtle aid 

 to vision than an achromatic glass would show the hidden artist, with 

 his plan before him, striving with skilful manipulation to perfect his 

 work. 



As life advances, and the young amphibian ranges the waters, the 

 terror of his insect contemporaries, not only are nutritious particles 

 supplied by its prey, by the addition of which to its frame growth takes 

 place, laid down, each in its proper spot, and in such due proportion 

 to the rest, as to reproduce the form, the color, and the size character- 

 istic of the parental stock ; but even the wonderful powers of repro- 

 ducing lost parts possessed by these animals are controlled by the same 

 governing tendency. Cut off the legs, the tail, the jaws separately 

 or all together and, as Spallanzan showed long ago, these parts not 

 only grow again, but the redintegrated limb is formed on the same 

 type as those which were lost. The new jaw or leg is a newt's, and 



