522 THE PHYSIOLOGY OF REPRODUCTION 



conclusion finds confirmation in the observation that variations in 

 diet are apparently capable of producing changes in the foetus. 1 It 

 was noted by l^tchhead and Cramer 2 that abortion occurred in 

 three out of six pregnant rabbits fed on a diet rich in carbohydrates 

 during the whole period of gestation. A similar observation is 

 recorded by Cramer and Marshall.- Wallace 3 states that cows ted 

 on molasses prove to IK? uncertain breeders, and Heape 4 that Lincoln 

 sheep fed solely on turnips are socially liable to abortion. 



According to Xoel Paton, 5 the size of the offspring; of the guinea- 

 pig dej>ends very directly upon the diet and nutrition of the mot her 

 during pregnancy. " To the physiologist it demonstrates the limita- 

 tions in the extent to which the tissues of the mother can be utilised 

 for the construction of the embryo. The nourishment of the maternal 

 tissues seems to take precedence over the nutrition of the foetus. 

 The mother appears to pass on the mrpltts nourishment to the foetus. 

 The better the nourishment of the maternal tissues, the greater the 

 growth of the foetus." This generalisation is too sweeping. Observa- 

 tions on rats have shown that the weight of the offspring remained 

 the same on different diets, although on one diet the mother increased 

 in weight during pregnancy while on the other it lost in weight. 

 Further, it has been proved in the pregnant rabbit that, when the 

 glycogen of the body is reduced to traces by repeated injections 

 of phloridzin, the placenta and tVetus still retain considerable amounts. 7 

 In this instance the needs of the fo?tus have taken precedence over 

 the storage of a carbohydrate reserve for the mother. Like Paton, 

 Prochownick 8 states that the size of the offspring may be markedly 

 diminished by restricting the diet of the mother (human female) ; but 

 many exceptions to this rule are found, which in fact comes into 

 operation only when the restriction of food has been severe enough 

 to jeopardise the health of the mother. 



This opens up another question : Does the expenditure few the 

 embryo entail loss to the mother '. " If the mother must transfer 

 a part of her own bodily substance to the germ, the loss is of little 



1 Thieinich was, however, unable to discover any difference in the constitu- 

 tion of the fietal fat, after feeding the mother on widely different fats 

 (see p. 543). 



- See Cramer and Marshall, " A Note on Abortion as a result of a Diet rich 

 in Carbohydrates," Jon,-. f K<-n. /;/<-/., vol. iii., 1908. 



3 Wallace, /'"//// !/,,; Sto<-k, 1907. 



4 Heape ascribes the frequency <>f abortion to the fouling of the turnip-roots 

 by mud and excrement, a condition of things which results from overcrowding. 

 See .A-"/-. lli,<i. Atin'i: ,W., 1899. 



' Noel Paton, "The Influence of Diet in Pregnancy on the Weight of the 

 Offspring," /.,,,'/. 1903. 



' Cramer (W.), Unpublished observations. 



Lochhead and Cramer, "The Glvcogenic Change> in the Placenta and the 

 s of the Pregnant Rabl.it," /'/," AW 8oc. London, P.., vol. Ixxx., 1! 



ProehownicK, Tl^rnj,. .}[i,,mt ! tl.eft<; i'*)l, quoted by Paton (/. n't.). 



