How to keep fit : a series of special lectures to young men delivered at the Central Y.M.C.A., London / by W. McAdam Eccles [and others].

Date:
[1914?]
Catalogue details

Licence: In copyright

Credit: How to keep fit : a series of special lectures to young men delivered at the Central Y.M.C.A., London / by W. McAdam Eccles [and others]. Source: Wellcome Collection.

    21/142 (page 17)
    eggs. And I want you particularly to notice this non-alcoholised tadpole, how well it is becoming developed. Here are gills at the side of the head. Yet you will notice that the other—the alcoholised tadpole—shows hardly any evidence of gills. We now go a stage further, and the next slide will show us these tadpoles after further develop- ment—fourteen days. Here is the tap-water tad- pole. He has produced quite a big body, and is beginning to grow his little legs. This alcohol- water tadpole, on the other hand, is still small as compared with the others, and you have still got an egg or two in existence. Next we come to the six weeks’ stage. Now at six weeks they are beginning to get very active and exceedingly difficult to photograph, although taken by rapid photography. You will notice with the tap-water tadpole we have actually got three tails —or rather three impressions of the one tail— because he is flapping it about so rapidly ! In the alcoholised tadpole there are only two instead of three impressions, showing that the tail is not moving quite so rapidly. In other words, these tadpoles are unfit as compared with the others. The next slide is of two chickens. These young chickens were hatched from the eggs of the same hen. They were placed in an incubator on the same day. The egg from which that chicken came was painted over with a solution of water contain- ing two per cent, of alcohol. This chicken came from an egg which was not so treated. I know some will say that if you use ordinary tap water you will get the same thing. But you do not, and B