161 



The blood was supposed to contain all the complex substances 

 poured out by dift'erent glands, and it was simply the duty of 

 the gland-cell to choose from the blood, as it flowed by, the 

 particular substance that it was required to separate. Now, 

 however, the gland-cell is known to fulfil a more important 

 office. Formation rather than separation, would apjjcar to be 

 the function of the gland-cell. It would seem to attract the 

 nutrient material in its vicinity, and with unknoAvn machinery 

 to make use of chemical affinity to construct elaborate com- 

 pounds. But we cannot gauge the action of a gland by merely 

 analysing the secretion poured out, for there can be little 

 doubt that all glands compound for the blood as well as 

 for their own secretion. This has been shown to be the case 

 in the liver, and we have no right to consider this gland as 

 an exception. But besides thus refunding secretions of a com- 

 plex nature, we must remember that an equivalent debasing 

 action must take place, and as the cell itself must be restored, 

 more fuel than is at first sight apparent is required. In some 

 cases these debased materials are poured out in the gland's 

 secretion ; in others they are returned to foul the blood until 

 it has passed through one of the refining glands. 



We acknowledge that all this work emanates from the cell. 

 Can we no further localise it ? I think we can. In certain 

 cases we are able, from the insolubility of the secretion, to 

 observe the position it occupies when it is first formed. In 

 such cases we see the secretion within the plasm. The exact 

 site it there occupies is not perhaps of much importance, since 

 we are aware of the existence of outward currents in the 

 plasm. Still, certain observations that will be mentioned 

 directly afford evidence of its being formed in actual contact 

 with the nucleus. If this be so, it matters little whether in 

 one case the secretion is seen to be intranuclear, in another 

 adnuclear, or in a third circumnuclear, for it must be re- 

 membered that our nuclear matter is shut off from the plasm 

 by no partition wall. In studying the physiological anatomy 

 of the mammary gland during the secretion of milk, I think I 

 have been clearly able to understand how some of the fallacious 

 notions concerning the cell and its function have arisen. 



In all cases when lactation first sets in, we find in the milk 

 certain structures known as colostrum-corpuscles. These 

 have been correctly regarded as altered gland-cells, and they 

 can be shown to be vesicular ; to consist of cell- walls and 

 cell-contents, with a nucleus or a remnant of one. But if we 

 examine the secretion Avhen the gland is in full v.orking order, 

 we find no colostrum-corpuscles, no cell remains of any kind. 

 On examiuirig the gland itself this may be accounted for. 



