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 effect shedding of epidermis or 
