I'EBKUABY 6, 1920] 



SCIENCE 



127 



the antique, or a good sense of perspective, 

 but they have left their mark on the edifice. 



Two somewhat paradoxical if not antithetic 

 achievements in botany stand out conspicu- 

 ously in the last quarter-century or so : in- 

 creasing assimilation of the science itself with 

 cognate sciences into the broader science of 

 life — biology; and an increasing tendency for 

 its own members, differentiating into organs, 

 to segregate into offsets and strike root for 

 themselves. 



To-day we rarely hear any one talk of the 

 food of plants being inorganic, and that of 

 animals, organic; we hear, rather, of green 

 plants as the food makers of the world. Even 

 the word assimilation has fallen into disuse or 

 become hyphenated as applied to this process. 

 Digestion, metabolism, nutrition, have become 

 subjects of parallel investigation in the two 

 branches into which the tree of life has 

 evolved. 



The incipient stage of cell division, with 

 qualitative bipartition in its somatic stages 

 and qualitative segregation in the formation 

 of gametes in all but the very lowermost of 

 protista, has become so largely known as to 

 make it hard to think of any bit of existing 

 protoplasm as other than a fragment of one 

 primordial protoplast, or ito think of a proto- 

 plast of today as not genetically related to 

 every other protoplast past or present. 



The chemico-physical activities of plant and 

 animal no longer claim attention as separate 

 problems; absorption, selection and rejection 

 of material, ionization, diffusion, osmosis — 

 all have become biological rather than zoolog- 

 ical or botanical questions, as they pertain to 

 living things; but botanists are doing their 

 full share toward answering them. 



That botanical investigation should have 

 demonstrated Mendel's law two generations 

 ago or exhtuned it two decades ago, places 

 this discovery among the achievements of 

 botany; but on it has been founded the bio- 

 logical superstructure of genetics — as valued 

 an adjunct of the stockbreeder as of the 

 breeder of plants. That a botanist differen- 

 tiated between fluctuations and mutations and 

 so simplified the understanding of natural 

 selection has not prevented that differentiation 



penetrating into every branch of evolutionary 

 investigation. 



That toxins became known when the activi- 

 ties of bacteria were studied, has not pre- 

 vented the student of animal physiology from 

 carrying the same study of excreta into the 

 relations of animal parasites and their hosts, 

 or from developing from it the theory of auto- 

 intoxication. Enzymes, hormones and vita- 

 mines — whatever either may be, now lie in the 

 common field of biology, but some of the best 

 work on them is done by botanists. 



Out of the harmonies and disharmonies of 

 plants with the manifold kinds of environ- 

 ment that the world offers, has developed a 

 line of ecological observation, experimenta- 

 tion, and speculation that not only has 

 brought the microscopic algse of the world- 

 plankton into recognition as the first fruits 

 and the foimdation of all aquatic life, past 

 and present, but points as unmistakably to the 

 individual birth, adolescence, mature life and 

 senescence of a fiora as the experience of 

 agronomy does for a plant or recorded history 

 does for a community of men: it has passed 

 forever from the kodak-census stage. 



Incursions into the no-man's-land confront- 

 ing science are increasingly paralleling the 

 phenomena that ecology deals with. The 

 rapid invasion of an army of men, or a swarm 

 of locusts such as I have seen blackening the 

 sky in Central America, carries its own sug- 

 gestion of impending conquest or devastation. 

 The trickling of a thin thread of water 

 through the dike, the exploration of a few 

 pioneers or the settling of a few families be- 

 yond the front, may escape notice as sig- 

 nificant; and the army may be driven back 

 or the grasshoppers stopped by attention to 

 their breeding places. The most-heralded ad- 

 vances sometimes prove the least important, 

 and the humblest, the most significant, in 

 retrospect. 



Who but a croaking pessimist would have 

 dreamed that an miknown fungus spore 

 dropped on the Emerald Isle would lead to 

 famine and starvation affecting a large popu- 

 lation of men; that a rather iminteresting 

 imperfect fungus added to the local flora of 

 !N"ew York would cause the magnificent chest- 



