THE NEW CELL DOCTRINE 21 



speak, non-saturated protoplasm, into which a number of 

 spermatozoa make their way and maintain themselves for 

 some time, disappearing, however, in a few hours, and ap- 

 parently in the same measure as the influence of the fertiliza- 

 tion proper expands. In animals, which have relatively 

 small eggs, the whole becomes more rapidly saturated by 

 fertilization, so that only one spermatozoon can go in. 



We spoke before of the great influence of small quan- 

 tities upon the protoplasm. It is certainly the greatest ad- 

 vance of modern physiology that we have become better 

 acquainted with the significance of this phenomenon. We 

 have here to consider especially a new kind of action at a 

 distance which takes place constantly in our own bodies. 

 When, forty years ago, I made my first physiological experi- 

 ments, the nervous system was the only means known to us 

 to effect action at a distance within the animal body. We 

 studied industriously nerve fibers, sensations in the brain, 

 and the stimuli which passed from the central nervous system 

 to the various organs of the body. Since then we have dis- 

 covered the phenomenon of so-called internal secretion. The 

 glands form secretions which are further used in the body. 

 The majority of glands have a duct which carries off the se- 

 cretion; thus, for example, in the case of the liver we have the 

 ductus hepaticus which conducts the secretion of the liver 

 to the intestinal canal. It is known now, however, that there 

 are glands which have no duct, Fig. 14. Nevertheless, these 

 form secretions which are delivered immediately to the blood 

 and then are distributed by means of the circulation through 

 the entire body. It has been learned that each internal secre- 

 tion, which is formed in very small quantities, exerts a sur- 

 prisingly great influence on other parts of the body which 

 may be quite remote from the gland. I may mention as in- 



