Page:Popular Science Monthly Volume 71.djvu/204

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POPULAR SCIENCE MONTHLY

The change from rapid to slow decline is not sudden, but gradual, as you see by the general character of this curve.

In the next slide we can see immediately that what I have asserted as true of the male is equally true of the female, although the values

PSM V71 D204 Graph of the daily percentage of weight increments of female guinea pigs.png

Fig. 22. Curve showing the Daily Percentage Increments in Weight of Female Guinea-pigs.

which we have differ slightly in the two sexes, and there are accidental but not significant variations in this curve as in the first. Here also we observe at once an early period of rapid decline in which the rate of growth is going down and down—a period of slight decline in which, to be sure, it is going down still, but with diminished rapidity.

There is another method by which we can represent this change

PSM V71 D204 Graph of the time lapse for a 10 pc increase of male guinea pig weight.png

Fig. 23. Curve showing the Length of Time required to make Each Successive Increase of 10 per cent, in Weight by Male Guinea-pigs.