722 
ON THE GESTATION OF COWS. 
phlebitis occurred, and she had been bled a week before for the same 
reason. I did not lose the opportunity of endeavouring to discover 
the cause of this disposition to colic, and I began to trace the whole 
course of the bowels. In a part of the small intestines I discovered 
an introsusception of nearly two feet of the small intestine into the 
contiguous portion. The part within the other was a little thickened ; 
but neither it nor the external portion, nor the mysentery thereto 
attached, were in the least inflamed or diseased. I could not dis- 
cover any thing else unusual throughout the whole course of the 
bowels. 
ON THE GESTATION OF COWS. 
By the Right Hon. EARL SPENCER, President of the English 
Agricultural Society. 
[Read May 25, 1839.] 
For the purpose partly of curiosity, and partly because I thought 
the notions entertained respecting the ordinary period of the gesta- 
tion of cows incorrect, I, several years since, began to take 
notes, whenever a cow calved, of the length of time she had been 
pregnant; and having now the periods of gestation of 764 cows 
taken in this way, I think a sufficient number of cases has been 
collected to enable me to draw general conclusions from the obser- 
vations which T have made. I certainly am not aware of any 
practical use to which the knowledge of the results to which I am 
about to draw the attention of the English Agricultural Society 
can be applied; but as they are connected with the physiology of 
cattle, and they differ from statements made in some books of de- 
servedly high authority on agricultural science, I think they may 
be considered sufficiently interesting to induce the Publication 
Committee to insert this paper in their Journal. 
In order more clearly to bring under the view of the English 
Agricultural Society the conclusions to Which my observations 
have led me, I shall begin by inserting a table, which will shew 
how many cows producing live calves have gone each of the dif- 
ferent periods therein mentioned. The first column shews the 
number of days of gestation; the second, the number of cows 
which have gone each period ; the third and fourth columns shew 
whether the produce was a cow calf or a bull calf; the fifth, if it 
was twin cow calves; the sixth, if it was twin bull calves; and 
the seventh, if it was twins of different sexes. For instance, if 
279 is taken, it will appear that 32 cows went 279 days; thatT6 
of them produced cow calves, 11 of them produced bull calves, 3 of 
them produced twin cow calves, none of them produced twin bull 
calves, and 2 of them produced twins of different sexes. 
