PRIMORDIAL UTRICLE. 



being filled with watery matter. In some instances, this 

 change proceeds until mere protoplasmic threads are seen 

 stretched across the cavity. The transparent fluid material 

 occupying the spaces and the intervals between the threads 

 is supposed to be the less important matter, and yet it is 

 the living, growing, and moving substance ; while the 

 threads and walls of the spaces are composed of matter 

 which has ceased to manifest these properties matter 

 which no longer lives, and which has been formed from the 

 living matter. But we may fairly ask if this lifeless, passive, 

 formed matter, which cannot move or grow or multiply of 

 itself, which is but a product of the death of protoplasm, 

 is nevertheless to be called by the same name as the living, 

 moving substance which it once was ? If this be so, there 

 ought to be no recognizable difference between matter 

 which is actually alive and the substances which result from 

 its death. 



So far, then, we have seen that the term protoplasm has 

 been applied to the matter within the primordial utricle of 

 the vegetable cell, to that clear substance which undergoes 

 vacuolation and fibrillation, and to the matter forming the 

 walls of the vacuoles and the threads or fibrillae. Still more 

 recently, Von Mohl's primordial utricle has been called proto- 

 plasm by Professor Huxley, who some years before restricted 

 the term to the matter within the primordial utricle, which 

 matter at that time he regarded as an " accidental anatomi- 

 cal modification" of the endoplast, and of little importance.* 

 The nucleus, and with it the protoplasm, Mr. Huxley 

 thought, exerted no peculiar office, and possessed no meta- 

 * "The Cell Theory," ' Med. Chir. Rev.,' October, 1853. 



