NUTRITION AND GENESIS. 459 



the ill-fed individuals. On the high and coraparativoly- 

 infertile Cotswolds, it is unusual for Ewes to Lave twins ; but 

 they very commonly have twins in the adjacent rich valley of 

 the Severn. Similarly, among the barren hills of the west of 

 Scotland, two lambs will be borne by about one Ewe in twenty ; 

 whereas in England, something like one Ewe in three will 

 bear two lambs. Nay, in rich pastures, twins are more 

 frequent than single births ; and it occasionally happens 

 that, after a genial autumn and consequent good grazing, a 

 flock of Ewes will next spring yield double their number of 

 Iambs — the triplets balancing the uniparse. So direct is this 

 relation, that I have heard a farmer assert his ability to fore- 

 tell, from the high, medium, or low, condition of an Ewe in 

 the autumn, whether she will next spring bear two, or one, 

 or none. 



§ 355. An objection must here be met. Many facts may 

 be brought to prove that fatness is not accompa/.ied by ferti- 

 lity but by barrenness ; and the inference drawn is that high 

 feeding is unfavourable to genesis. The premiss may be 

 admitted while the conclusion is denied. 



There is a distinction between what may be called normal 

 plethora, and an abnormal plethora, liable to be confounded 

 with it. The one is a mark of constitutional wealth ; but the 

 other is a mark of constitutional poverty. Normal plethora 

 is a superfluity of materials both for the building up of 

 tissue and the evolution of force ; and this is the plethora 

 which we have found to be associated with unusual fecundity. 

 Abnormal plethora, which, as truly alleged, is accompanied 

 by infecundity, is a superfluity of force- evolving materials 

 joined with either a positive or a relative deficiency of tissue- 

 forming materials : the increased bulk indicating this state, 

 being really the bulk of so much inert or dead matter. Note, 

 first, a few of the facts which show us that obesity implies 

 physiological impoverishment. 



Neither in brutes nor men does it ordinarily occur either 



