664 MECHANISM OF THE SECRETION OF Mil A'. 
(paralytic) secretion of saliva after section of the chorda tympani. 
Likewise, the effects which have been got by stimulating the cut nerves, 
and which have been usually in the direction of diminishing the 
quantity of the secretion, may well be ascribed to vasomotor changes 
rather than to direct nervous influence. All that can be said, 
therefore, on this question is to repeat the statement, that the 
experimental evidence of such an influence is still lacking, however 
probable its existence may be from the everyday experience of changes 
produced in the milk of nursing women, as the result of emotional 
conditions. 
Action of pilocarpine and atropine. — The drug which has the most 
marked effect in increasing most of the secretions of the body, namely, 
pilocarpine, is stated to have little or no effect upon the secretion of 
milk. 1 On the other hand, atropine is well known to be constantly 
employed for nursing women, in whom, for one reason or another, it 
is desired to dry up the secretion. Short, however, of stopping the 
secretion altogether, atropine, given in smaller doses, is found, whilst 
diminishing the amount of fluid secreted, to cause the secretion of a 
more concentrated milk. 2 
Influence of diet. — The quantity and quality of the food is well 
recognised as having an important influence on the quantity and quality 
of the milk. The most abundant and richest milk is yielded when the 
diet is liberal, and, in the case of carnivora (bitch) certainly, but less 
certainly in the case of herbivora (cow), when it includes a larger pro- 
portion than usual of proteid material. And it is not so much the 
albuminous constituents of the milk (casein and lact-albumin) which are 
increased, but especially the proportion of fat. 3 This indeed has been 
held to be one of the most cogent arguments in favour of the view 
contended for by Yoit, that animal fat is formed mainly from proteids. 4 
An increase of fat in the food, without a simultaneous increase of 
proteid, does not cause an increased secretion of fat in the milk. 1. 
Not only the amount of proteids and fat, but also the amount of sugar, 
is increased as the result of giving proteid-rich food. 6 Alcohol, given to 
goats, has also been found to increase the fat of milk. 7 
It does not, of course, follow that because an excess of a particular organic 
principle in the food produces an increase of certain constituents of the milk, 
that these constituents are directly produced from such material, for the effect 
may be produced indirectly by the functions of the gland-cells becoming 
modified, according to the nature of the pabulum they are receiving. Looked 
1 Hammarbacher (goat), Arch. f. d. gcs. Physiol., Bonn, 1884, Bd. xxxiii. S. 228; 
Cornevin {Compt. rend. Soc. dc MoL, Paris, 1891, p. 628) found that in the cow the amount 
of milk yielded was not influenced by the daily injection of - 25 grm. pilocarpine. See 
also Mironow, loc. cit. 
- Hammarbacher, loc. rib. 
3 The evidence for this is given by Heidenhain (Hermann's " Handbuch," 1882, Bd. v.). 
where also all the most important references on the influence of diet up to that date will be 
found. The following may also be cited — W. Kirchner, Milchze'dung, 1891, Bd. xx. ; 
C. Schneider, " Einfluss versch. Futterung auf d. Zusammensetz. der Milch," Diss., 
Leipzig, 1893. 
4 See article on "Metabolism." 
5 Ssubotin, Virchow's Archiv, 1866, Bd. xxxvi. ; Cenfralbl. f. d. med. Wissenscli., Berlin, 
1S66, S. 337; Kemmerich, ibid., S. 467; Kuhn, Journ. f. Lavdwirthsch., 1876, S. 381; 
Weiske, ibid., 1878, S. 447; Cf. also Juretschke. "Einfluss versch. Oelkuchensorten auf 
dem Fettgehalt der Milch," Diss., Leipzig, 1893. 
B I. Munk, Arch. f. vtissensch. u. prakt. Thicrh., Berlin, 1881, Bd. vii. S. 91. 
7 Stumpf, DeutxchcsArch.f. Min. Med,, Leipzig, 1882, Bd. xxx. S. 201. 
