HEREDITY 203 



extend their meshes so as to enclose the cells 

 and keep them under their immediate influence, 

 communicating to them their mode of working, 

 increasing, diminishing, or paralysing their working. 



Two words only to explain the mode of innerva- 

 tion in the glands, and see at the same time how 

 all social phenomena have their origin in biological 

 conditions, and how it is known that these depend 

 upon physics and chemistry, to evidence the unity 

 of the cosmos. 



The progress of humanity depends strictly upon 

 physiology, as the action of the lungs upon the air. 



Fig. 23 is taken from a note of MM. E/amon y 

 Cajal and D. jClaudio Sala y Pons, 1 its object 

 being to demonstrate the nerve-terminations in 

 the interior of the glands. These authors state : 

 " After several operations of dichotomy and being 

 reduced to fine varicose branches they constitute a 

 tight nerve-plexus around the acini, the very delicate 

 stems of which touch the outside of the glandular cor- 

 puscules (fig. 23, a). From the periacinous filaments 

 start fine little threads which, penetrating into the 

 separative cement of the epithelium, end freely a 

 little further off, by means of a granulation (fig. 23, b), 



, ! I avail myself of this opportunity to thank Dr D. Claudio Sala 

 y Pons for his kindness in drawing the figures in this book, and at the 

 same time to express my gratitude, for his knowledge of neurology has 

 been of great service to me in completing the chapters relating to the 

 phylogeny and ontogeny of the neurona. 



