. The anatomical record. Anatomy; Anatomy. 272 HELEN DEAN KING sake of uniformity this record is put under the mean age '570 days' which is thus extended to include a period of forty-four days. The majority of female rats that are in good physical condi- tion cast their first litters when they are about three months old. Tliirty-eight of the seventy-six breeding females bore young before they were 105 days old; all of the remaining females,. Fig. 1 Graph showing, for the entire series, the relation of the age of the mother to litter production (data in table 2). with four exceptions, threw lit
. The anatomical record. Anatomy; Anatomy. 272 HELEN DEAN KING sake of uniformity this record is put under the mean age '570 days' which is thus extended to include a period of forty-four days. The majority of female rats that are in good physical condi- tion cast their first litters when they are about three months old. Tliirty-eight of the seventy-six breeding females bore young before they were 105 days old; all of the remaining females,. Fig. 1 Graph showing, for the entire series, the relation of the age of the mother to litter production (data in table 2). with four exceptions, threw litters before they reached the age of 135 days. As table 2 shows, the number of litters cast in- creased with the age of the mothers until the females attained the mean age of 210 days. After the age of maximum fertihty was passed the number of litters cast decreased rapidly, and only a small proportion of the females bore young after they had reached the age of fifteen months. The graph in figure 1, constructed from the litter data in table 2, shows the relation of the age of the mother to litter Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bardeen, Charles Russell, 1871-1935, ed; Boyden, Edward A. (Edward Allen), 1886-1976; Bremer, John Lewis, 1874- ed; Hardesty, Irving, b. 1866, ed; American Association of Anatomists; American Society of Zoologists; Wistar Institute of Anatomy and Biology. [New York, etc. ] A. R. Liss [etc. ]
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectanatomy, bookyear1906
