Beard, On the Occurrence of Dextro-rotatory Albumins in Organic Nature. |ti~) 



killed and pulled to pieces, whilst the Daphnids survived. This is 

 possibly the first occasion, on which in close association together 

 in nature Hydra was impotent to kill its prey, Daphnia pulex. 

 Without doubt it is by means of a ferment that Hydra kills Daphnia. 

 This fact answers by anticipation an objection, which may be raised, 

 that Daphnia is protected from the action of trypsin and arnylopsin 

 by its chitinous covering. This latter is no protection whatever 

 against the antithesis of trypsin, the ferment produced by the stinging 

 cells of Hydra. Indeed, it is not too much to say, that the result 

 of the experiment with Hydra and Daphnia alone would suffice to 

 establish the existence of two categories of albumins at least, laevo- 

 rotatory and dextro-rotatory respectively. 



With Em il Fischer I maintain, that "the enzymes are quite 

 especially valuable - as means of recognition of stereochemical 

 differences", and that "of two molecular looking-glass image forms" 

 in the present case living albumins of animals - "the one is 

 broken up by enzymes under the same conditions under which the 

 other remains intact". His examples were the glucosides: mine 

 the living albumins of certain animal organisms. Two examples 

 were held by him to suffice to establish his theses: for mine more 

 than two are adduced, and, moreover, if shown to be desirable, 

 the number can be increased very considerably. For, in fact, the 

 organisms employed in the actual experiments were but samples, 

 chosen in hap-hazard fashion, of a large series of micro-organisms 

 or developing organisms, all of which - - and their name is legion - 

 would, if identified embryologically as asexual generations, 

 exhibit the same phenomena of death and disintegration in the 

 presence of active pancreatic ferments. The asexual nature of 

 the organisms experimented upon as such had been decided previ- 

 ously, and upon other than chemical grounds, that is, from develop- 

 mental and biological data. Not a single one of the experiments 

 failed to confirm the biological conclusion. 



On the present occasion it is not my intention to examine the 

 bearings of the facts and conclusions upon ordinary zoological 

 problems, for to do so would carry the discussion too far. Possibly, 

 it may now be recognisable, that the heretical preaching of anti- 

 thetic alternation of generations in the wilderness in past and recent 

 years had its fount in scientific truth. Possibly, it may become 

 evident, that in some groups of animals, such as sponges, ctenophores, 

 sea-anemones, and corals, as well as in Hydra and Cordt/lophora, 

 the sexual generation is not represented except by the forerunners 

 of the sexual products, eggs and sperms. 



It is, however, the duty of the scientific investigator to draw 

 the conclusions from his observations and experiments, and this I 

 shall now proceed to do in certain interesting and obvious direc- 



