324 BROOKLYN BOTANIC GARDEN MEMOIRS 



morning after a definite number of days of growth, is as indicative for 

 that fungus as is the previous growth of Mucor on the same medium, 

 within a shorter period. 



What conclusions, it may now be asked, can be drawn from data 

 such as the few above given? 



Time, space, energy and matter are the four great interrelated 

 phenomena of the world, as of the universe generally. Not a few 

 physicists now question the existence of the last of these, but inert 

 and mobile ether particles as focal centers and pathways for "tubes 

 of energy" seem to be helpful — even necessary requirements. For by 

 their gradual aggregation under increasing condensations of energy we 

 can explain the origin of the elements, and equally the compounds of 

 these. But the fundamentally important consideration is how, when, 

 and to what extent in given times, do definite tubes of energy distrib- 

 ute themselves. 



In the foregoing pages a set of simple facts has been recorded that 

 any average observer might accumulate. But the real value of many 

 of them has been overlooked, because we have not fully realized the 

 significance of the causes that bring them about. For in the past we 

 have largely viewed biological phenomena as static or semistatic exhi- 

 bitions of so much material substance. But we have in great measure 

 failed to realize that matter as such is physically passive or inert, and 

 that the fundamental moving, transforming, upbuilding, and dis- 

 integrating agency in all of the above phenomena of phytophenology 

 consists in definite expenditures of definite amounts of energy along 

 definite material pathways. Or to use Faraday's phrase as applied 

 to inorganic changes, we are dealing with "tubes of energy" that are 

 distributed along definite material pathways, at stated climatic periods, 

 and that are marvelously exact for any one species, or any one organ 

 of a species. 



In the process these tubes of energy are exactly expended so as 

 to stimulate the inert material particles to take up water, to digest 

 or metabolize reserve products, to convey the metabolized products 

 to definite cells or cell walls, to build these up into new material 

 linkages or combinations, and in the process to effect growth of leaves, 

 opening of flowers, dehiscence of anthers or of sporangia, maturation of 

 ovules and extrusion therefrom or from some accessory part at exactly 

 appropriate time of viscous entangling secretions that strand the 

 pollen grains, and that in time aid in the germination of these; or 

 again that start like initial changes in dormant seeds, once so many 

 units of heat, moisture, and oxygen have cumulated as summated 

 tubes of energy after a definite period of time; or that develop new 

 cells or transform older ones, so as to efi'ect shedding of epidermis or 



