24 A CRITICAL PERIOD IN THE DEVELOPMENT OP THE HORSE. 



established may well be left to breeders and veterinarians. I 

 may, however, in conclusion, make the following suggestions : — 



1. That mares which have been indoors during the winter, and 

 which are to run at grass during the summer, should be, as it 

 were, acclimatised before they are served, i.e., they should be 

 allowed to run out night and day for two or three weeks, in order 

 to have time to adapt themselves to the change of food, the some- 

 what marked variations of temperature, and to their new sur- 

 roundings generally. 



2. That mares, more especially excitable ones, should be served 

 in the evening, and shut up apart from other mares or geldings 

 during the night. They should then, until the periodic disturb- 

 ance has subsided, be kept in a paddock as far removed as possible 

 from mares or geldings likely to tease them. 1 



3. That when any signs of oestrum are detected in a mare 

 (whether she has been previously presented to the horse or not), 

 she should be removed from mares believed to be already in foal. 



4. That each mare should be carefully watched from week to 

 week, and periodically — every ninth or tenth day — tried until 

 the critical period has been successfully passed. 



5. That mares backward and out of condition in the spring 

 should be allowed for some weeks oats at least once a day ; for 

 unless they are in a healthy and vigorous state, ova may not be 

 discharged until the summer is well advanced; or, if ovulation 

 takes place, the eggs may be so impoverished that the embryo 

 may fail to survive the critical period, or, if it succeeds in this, 

 develop into a small, weedy foal. It is all but impossible, 

 apparently, for a mare to produce strong, vigorous twins capable 

 of eventually reaching the size of their parents. This is evidently 

 a matter of nourishment. Hence, if the dam is out of condition, 

 or if the foetal circulation is weak, or the allantoic villi in any 

 way unsatisfactory, the foal, if born alive, is not likely to be a 

 source of credit or profit to the breeder. 



1 This year a very healthy, well-bred, cream-coloured mare, though repeatedly 

 served by the zebra during the months of March, April, and May, did not settle. 

 She was again served by the zebra on the 23rd and 25th of June, and then placed 

 in the hands of a breaker, so that she might, if necessary, be sold. I have every 

 reason to believe she is now (July 1897) holding. Probably we were at last suc- 

 cessful, because this mare was taken in from grass and kept regularly at work. 



