BULLETIN No. 204. 



A CASE OF TRIPLET CALVES: WITH SOME 



GENERAL CONSIDERATIONS REGARDING 



MULTIPLE GESTATION IN NORMALLY 



UNIPAROUS ANIMALS/ 



Bv Raymond Pearl. 



Introduction. 



Some five years ago the writer became interested in the 

 general subject of the occurrence of multiple gestation in animals 

 normally bearing but one 3'-oung at a birth, through having his 

 attention called to a case of triplet calves. A brief preliminary 

 notice of the case was published at the time.^ 



It was then intended immediately to follow this note with a 

 more detailed discussion of the case. As material was collected 

 in the preparation of that paper, however, it soon became evi- 

 dent that such cases of multiple pregnancy presented a number 

 of features of interest in connection with certain general prob- 

 lems of biology. As time went on it seemed desirable to extend 

 the scope of the inquiry. Accordingly I have been collecting 

 notes and data on the general subject during the past four 

 years. It seems desirable now to> put some of these notes to- 

 gether for publication. 



There are four general biological problems to which cases 

 of multiple gestation relate and upon which we may reason- 



'Papers from the Biological Laboratory of the Maine Agricultural 

 Experiment Station, No. 39. 



^Pearl, R. A Case of Triplet Calves with Peculiar Color Inheritance. 

 Science, N. S. Vol. 26, p. 760, 1907. 



