CHAPTER XI 



" We cannot reason with our cells, for they know so much more than we 

 do that they cannot understand us ; but though we cannot reason with 

 them, we can find out what they have been most accustomed to, and what 

 therefore they are most likely to expect ; we can see that they get this, as 

 far as it is in our power to give it them, and may then generally leave the 

 rest to them." SAMUEL BUTLKR. 



I. THE STIMULUS FOR THE MATERNAL CHANGES 



THE anatomical and physiological changes which occur in 

 the maternal organism during pregnancy are manifold. They 

 affect not only the generative system, but the body in general. 

 They are associated with the supply of nutriment and energy 

 for the formation of a new organism in the uterus, and the 

 preparation for its maintenance in the succeeding period. 



What constitutes the original stimulus for the changes that 

 occur in pregnancy remains still outside our ken. At least the 

 influence of the cerebrum is not all-important, as is shown by 

 the occurrence of normal pregnancy and lactation in women 

 suffering from paraplegia (Brachet, 2 Kruieger and Offergeld 3 ). 

 Similarly, transection of the spinal cord in the lumbar region 

 has no effect on pregnancy in the dog (Goltz 4 ). Further, 

 Goltz and Ewald 5 have proved the absence of any spinal reflex 

 influence in the dog by removing the entire lumbar cord 

 without disturbing the onset and progress of pregnancy. 

 Kruieger and Offergeld state, as the result of numerous experi- 

 ments, that the central nervous system has no influence, and the 



1 By James Lochhead. 



2 Brachet, Recherchea, 2nd Edition, Paris, 1837. 



3 Kruieger and Offurgeld, "Der Vorgang von Zeugung, Schwanger- 

 schaft," &c., Arch.f. Oyndk., vol. Ixxxiii., 1908. 



4 Goltz, " Ueber den Einfluss des Nervensystems auf die Vorgiinge wahrend 

 der Schwangerschaft," &c., PJtiiger'a Arch., vol. ix., 1874. 



* Goltz and Ewald, " Der Hund mit verkiirztem Riickenmark," Pfliiger'a 

 Arch., vol. IxiiL, 1896. 



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