66 4 MECHANISM OF THE SECRETION OF MILK. 



(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 thfc 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 freen 

 held to be one of the most cogent arguments in favour of the view 

 contended for by Voit, 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. 5 

 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. de biol., Paris, 1891, p. 628) found that in the cow the amount 

 of milk yielded was not influenced by the daily injection of 0'25 grm. pilocarpine. See 

 also Mironow, loc. cit. 



- Hammarbacher, loc. cit. 



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, Milchzeitung, 1891, Bd. xx. ; 

 C. Schneider, " Einfluss versch. Fattening auf d. Zusammensetz. der Milch," Diss., 

 Leipzig, 1893. 



4 See article on "Metabolism." 



5 Ssubotin, Firchow's ArcMv, 1866, Bd. xxxvi. ; Centralbl. f. d. med. Wissenscli., Berlin, 

 1866, S. 337; Kemmerich, ibid., S. 467; Kuhn, Journ. f. Landwirthsch. . 1876, S. 381 ; 

 Weiske, ibid., 1878, S. 447; Cf. also Juretschke, " Einfluss versch. Oelkuchensorten auf 

 dem Fettgehalt der Milch," Diss., Leipzig, 1893. 



6 I. Munk, Arch.f. wissensch. u. prakt. Thierh., Berlin, 1881, Bd. vii. S. 91. 



7 Stumpf, Deutsches Arch.f. klin. Med., Leipzig, 1882, Bd. xxx. S. 201. 



