374 



The Journal of Heredity 



color blind, and considerably less than 

 even that they would both be normal. 

 As to the conditions of the subject's 

 grandparents (I 1 and 2, 3 and 4), 

 which are not stated, it is possible only 

 to conjecture, though it is apparent that 

 both tlie grandmothers must have been 

 either color blind or heterozygous for 

 the- defect. The grandfathers might 

 have been color blind or not as far as 

 the data go. Nothing further can be 

 said about the paternal grandparents, 

 but the subject's mother having had 

 normal vision it is possible to say that 

 if his maternal grandmother (14) was 

 color blind her husband must have had 

 normal vision, whereas if she had nor- 



mal vision he must have been color 

 blind. That is, to give the results ob- 

 tained (heterozygous normal daughter 

 and color blind son) the mating must 

 have been N — X "« or n — ■ X Nn. 



It would have been interesting if he 

 had noted the condition of his brother- 

 in-law (III 1), that is, the husband of 

 his color-blind sister (III 2). It was a 

 foregone conclusion that all her sons 

 would have defective vision since she 

 herself was color blind, but any daugh- 

 ters would have served as an index to 

 the father's condition, since their vision 

 would have corresponded to his. As it 

 is, he may or may not have been color 

 blind. 



THE GESTATION OF THE CARABAO 



B. M. Gonzalez, 

 Associate Professor of Animal Husbandry, College of Agriculture, University 



of the Philippines. 



LITTLE is known about the breed- 

 ing habits of the carabao (Bos 

 biibalus), since these animals are 

 on the range most of the time. 

 They rarely go under shelter except 

 during the busy season of harvesting, 

 when they are tied close to the house 

 of the farmer, under a light bamboo and 

 cogon or nipa shed, and are fed on 

 sugar-cane leaves or rice straw. While 

 the crops are growing, the carabaos are 

 used in cultivating the crops, and are 

 grazed on vacant lots, on paths over- 

 grown with grass, or on the roadside. 

 At these times breeding is not likely to 

 occur, as these animals are herded more 

 or less individually by the children of 

 the farmers. 



After harvest, all the carabaos in the 

 neighborhood have the run of all the 

 fields in common, since fenced areas 

 are rather rare in the Philippines, and 

 it may be presumed that it is at this 

 period when breeding occurs. Carabaos 

 mature later than cattle, bulls hardly 

 breeding regularly before three years of 

 age, and cows usually bringing their first 



young at five, sometimes at four, but 

 rarely before that. Under such condi- 

 tions it is impossible to determine the 

 exact gestation of the carabao, and an 

 inquiry among the farmers elicits a var- 

 iety of answers ranging from nine to 

 thirteen months or more. 



With the acquisition of a small herd 

 of these animals by the College of 

 Agriculture, the cows were kept sep- 

 arate from the bull from the start, and 

 observations were made on their 

 estrum. The period of estrum of these 

 animals is very obscure, and the only 

 way we succeeded in breeding them 

 was by attempted matings of them at 

 frequent intervals. 



The figures obtained so far, while 

 few, are significant, inasmuch as they 

 are fairly uniform. Due to the reasons 

 mentioned above, observations on the 

 period of gestation of this animal will 

 probably never become numerous. At 

 the College we estimate that we lost 

 about half a year on an average for 

 each cow observed by not knowing the 

 exact time when each cow should be 

 bred, due to the obscurity of estrum. 



