GENESIS, HEREDITY, AND VARIATION. 359 



with Mr. Darwin's hypothesis of gemmules. We have to 

 assume that where a cauline bud emerges there are present 

 in due proportions gemmules of all the parts which will pres- 

 ently arise from it leaves, stipules, bracts, petals, stamens, 

 anthers, etc. We have to assume this though, at the time 

 the bud originates, sundry of these organs, as the parts of 

 flowers, do not exist on the plant or tree. And we have to 

 assume that the gemmules of such parts are duly provided 

 in a portion of adventitious callus, far away from the normal 

 places of fructification. Moreover, the resulting shoot may 

 or may not produce all the parts which the gemmules repre- 

 sent; and when, perhaps after years, flowers are produced 

 on its side shoots, there must exist at each point the needful 

 proportion of the required gemmules ; though there have been 

 no cells continually giving them off. 



Still less does the hypothesis of Prof. Weismann harmonize 

 with the evidence as plants display it. Plant-embryogeny 

 yields no sign of separation between germ-plasm and soma- 

 plasm; and, indeed, the absence of such separation is ad- 

 mitted. After instancing cases among certain of the lower 

 animals, in which no differentiation of the two arises in the 

 first generation resulting from a fertilized ovum, Prof. Weis- 

 mann continues : 



"The same is true as regards the higher plants, in which the first 

 shoot arising from the seed never contains germ-cells, or even cells 

 which subsequently become differentiated into germ cells. In all 

 these last-mentioned cases the germ-cells are not present in the first 

 person arising by embryogeny as special cells, but are only formed in 

 much later cell-generations from the offspring of certain cells of which 

 this first person was composed. (Germ-Plasm, p. 185.) 



How this admission consists with the general theory it is 

 difficult to understand. The units of the soma-plasm are 

 here recognized as having the same generative powers as 

 the units of the germ-plasm. In so far as one organic 

 kingdom and a considerable part of the other are concerned 

 the doctrine is relinquished. Eelinquishment is, indeed, 

 necessitated even by the ordinary facts, and still more by the 



