376 FCETAL DYSTOKIA. 



with the huge EngHsh Earns, he has observed fewer difficult births 

 than in flocks composed solely of Merinos. And Saint-Cyr states that 

 he has often seen little "Bressanne" Mares, which were put to big 

 Percheron or Anglo-Norman Stallions, foal without difficulty at the 

 ordinary period. We might also adduce the small female Ass coupled 

 with the Horse-Stallion, and which rarely suffers during birth. Abor- 

 tion or premature birth may be more frequently the consequence of 

 such " mesalliances." 



Though certain facts could be opposed to the above conclusions, yet 

 it must be admitted that the uniformly exaggerated development of the 

 foetus is not a very common cause of dystokia, and is, as a rule, only 

 so when the pelvis of the female is smaller than usual. So that we 

 must look rather to special conformation than exaggerated develop- 

 ment. And so far as conformation is concerned, we find that excessive 

 development of the croup, chest, or head have the principal influence. 



With regard to the head, it is indisputable that of the three regions 

 this most frequently proves an obstacle to parturition. In the Bitch this 

 is most particularly remarked. But it is also noted in other animals. 



Price, in his book on Sheep, mentions that a grazier in Appledore 

 employed Leicester Eams for several years, and obtained a breed with 

 very small heads and " kindly disposition "; but he did not approve of 

 them, because they were not sufficiently large, and did not fetch a good 

 price in the market. He therefore, in the summer of 1804, hired some 

 large Kentish Eams, in order to give size to his flock. In the following 

 lambing season, he lost twelve Ewes, from the immense size of the 

 lambs' heads, and he was obliged to "draw" (extract artificially) 

 nearly all his Ewe lambs. In 1806 he had the same difficulty, and 

 lost nine Ewes in a flock of two hundred and fifty, from this cause. 



Mr. Cartwright (Whitchurch) casually states that he has frequently 

 known of some Bulls "getting Calves with very large heads, and 

 causing great difficulty in calving; and the owners, finding what trouble 

 there was at calving-time, and the danger of losing their Cows, have 

 sold them, and obtained others whose breed have not this objection." 



Euelf and Baumeister,i in alluding to this subject, remark that in the 

 Bovine species it is nearly always the head which forms the chief 

 obstacle to birth ; and they refer for proof of this statement to the 

 small native Cows of Wurtemberg, which, when crossed by the original 

 Simmenthalern Bull, have often difficult labour, as the latter breed has 

 often a large head. 



And Schaack writes to Saint-Cyr, stating that for thirty years the 

 Cows in the district of Lyons were all put to a Bull remarkable for its 

 massive framework. The head especially was very developed, and as 

 the animal transmitted this conformation to nearly the whole of its 

 progeny, the size of the head of the foetus very often rendered parturi- 

 tion difficult. 



Breeding from immature undeveloped animals is almost certain to 

 produce laborious births ; and the reason for this is not difficult to find : 

 the genital canal, and particularly the pelvis, is not sufficiently de- 

 veloped for the passage of the foetus. A very striking instance of this, 

 as well as of very remarkable precocity in the Bovine species, is given 

 by Mr. Barker.2 



Influence of Food. — There is no convincing proof before us that the 



^ Op. cit., p. 247. 



^ Veterinary Journal, vol. iii., p. 336. 



