1896.] J- 03 [Bailey. 



causes of the iinlikenesses of plants, for plants ■which start like when they 

 germinate may be very unlike when they die. Given time and constantly 

 but slowly changing conditions, and the vegetable creation is fashioned 

 into the unlikenesses which we now behold. With this conception, let 

 us read again Francis Parkman's picturesque description of the forest of 

 Maine in his Half ■Century of Conflict: "For untold ages Maine had 

 been one unbroken forest, and it was so still. Only along the rocky 

 seaboard, or on the lower waters of one or two great rivers a few 

 rough settlements had gnawed slight indentations into this wilderness of 

 woods, and a little farther inland some dismal clearing around a block- 

 house or stockade let in the sunlight to a soil that had lain in shadow 

 time out of mind. This waste of savage vegetation survives, in some 

 part, to this day, with the same prodigality of vital force, the same 

 struggle for existence and mutual havoc that mark all organized beings, 

 from men to mushrooms. Young seedlings in millions spring every sum- 

 mer from the black mould, rich with the decay of those that had preceded 

 them, ci'owding, choking and killing each other, perishing by their very 

 abundance ; all but a scattered few, stronger than the rest, or more fortu- 

 nate in position, which survive by blighting those about them. They in 

 turn, as they grow, interlock their boughs, and repeat in a season or two 

 the same process of mutual suftocalion. The forest is full of lean saplings 

 dead or dying with vainly stretching towards the light. Not one infant 

 tree in a thousand lives to maturity ; yet these survivors form an innumer- 

 able host, pressed together in struggling confusion, squeezed out of sym- 

 metry and robbed of normal development, as men are said to be in the 

 level sameness of democratic society. Seen from above, their mingled 

 tops spread in a sea of verdure basking in light ; seen from below, all is 

 shadow, through which spots of timid sunshine steal down among legions 

 of dark, mossy trunks, toadstools and rank ferns, protruding roots, matted 

 bushes, and rotting carcases of fallen trees. A generation ago one might 

 find here and there the rugged trunk of some great pine lifting its verdant 

 spire above the indistinguished myriads of the forest. The woods of 

 Maine had their aristocracy ; but the axe of the woodman has laid them 

 low, and these lords of the wilderness are seen no more." 



In such bold and generalized examples as this, the student is able to 

 discern only the general fact of progressive divergency and general adap- 

 tation to conditions, without being able to discover the particular direc- 

 tive forces which have been at the bottom of the evolution. It is only 

 when one considers a specific example that he can arrive at any just con- 

 clusions respecting initial causes of modification. Of adaptive modifica- 

 tions, two general classes have been responsible for the ascent of the vege- 

 table kingdom, one a mere moulding or shaping into the passive physical 

 environments, the other the direct result of stress or strain imposed upon 

 the organism by wind and water and by the necessities of a radical change 

 of habit from aquatic to terrestrial life, and later on by the stimuli of in- 

 sects upon the flowers. One of the very best examples of the mere pas- 



