78 Scientific Intelligence. 



That endogens and exogens have had some common origin is, 

 in the first place, obvious from the numerous points of agreement 

 between their organs and tissues generally, as shown, e. g., in the 

 structure of their flowers and anatomy of their roots, etc.; but 

 the object of the present paper was to prove if possible, that 

 there was a more special connection between endogens and an 

 aquatic habit. 



The coincidences in points of structure between endogens 

 generally and the aquatic, and subaquatic exogens, as well as 

 such exogens as may reasonably be supposed to have had an 

 aquatic ancestry, are perhaps more numerous than the points of 

 agreement with exogens generally. Nature supplies us with 

 several " experimental verifications " in the alterations of struct- 

 ure in amphibious plants according as they live in water or on 

 the land. These coincidences may be thought sufficient to prove 

 that endogens have in the first place descended from very early 

 types of exogens which preceded them ; and that, secondly, the 

 more immediate cause of their origin was an aquatic habit of life 

 assumed by certain primitive exogenous plants. 



To state the process of adaptation in as few words as possible, 

 one might say that it was effected by means of the joint action of 

 the external influences or forces of the environment and the in- 

 ternal responsive power of living protoplasm, so that when a 

 terrestrial and aerial plant is grown in water, or a water-plant is 

 transferred to land, the direct action of the new environment com- 

 j^els the plant (provided it can survive the change), to alter its 

 structure so that the plant becomes at once adapted to the new 

 medium. The change from land to water brings on therefore 

 what may be called adaptive degenerations in every part of 

 the plant. Conversely, a transference from water to land induces 

 a tendency to restore the lost features, resulting, it may be, in a 

 greatly enhanced and vigorous growth. 



Whether there were several or few aquatic ancestors, or only 

 one, the author does not venture to suggest, although he hints at 

 the likelihood of there having been many. The difficulty in 

 dealing with this question lies in the fact that at present it is 

 impossible to trace affinities between the flowers of existing 

 endogens and those of any existing orders of exogens. The con- 

 clusions of this important paper have been given above substan- 

 tially in the words of the author, only a few unimportant changes 

 having been made. J g. l. g. 



IY. Miscellaneous Scientific Intelligence. 



1. The American Association for the Advancement of 

 Science. — The next meeting of the American Association for the 

 Advancement of Science will be held at Madison, Wisconsin, from 

 August 16th to 23rd. The President is Professor William 

 Harkness. 





