52 MASSACHUSETTS HORTICULTURAL SOCIETY. 



rather slow to make use of this clew through the otherwise track- 

 less labyrinth of forms, but it is today in the hands of even the 

 students of elementary botany, Avho can see in the fields of ripen- 

 ing wheat, with its ears of golden grain, leaves, and stems, and 

 roots — all much diversified ; and in the blue flax, the scarlet 

 runner, and the rose, leaves and stems and nothing more ; and 

 so in all the kindred of those plants which luxuriate in the 

 tropics. 



Eoots and stems are seldom so greatly disguised as to elude- 

 immediate identification, but sometimes leaves are so changed 

 from the familiar type as to defy detection except after close 

 study. But when we have made out the elemental parts and 

 have reduced our otherwise bewildering complex fractions of the 

 vegetable world to their lowest terms, we have before us the 

 materials for working otit the family history of plants. Before 

 this subject was made clear by the luminous suggestions of 

 Darwin and Wallace, the expression, " affinity in plants," was a 

 figure of speech rather than an expression of an undoubted fact. 

 How could this be otherwise when all held that species had come 

 down to us in straight lines without any variation wide enough 

 to carry one species beyond the limits which marked it from its 

 nearest neighbors ? But in the light of the hypothesis of deriva- 

 tion these lines are seen to be anything but straight : they are 

 tortuous beyond belief, and in their irregular course mark the 

 crooked path of descent. 



Therefore, we hold now that these widely separated plants in 

 all climates are, in the truest sense of the word, akin, and if we 

 may borrow a phrase from the sister kingdom, they are of one 

 blood. This belief lends a new charm to all examinations of the 

 diversified organs of plants, and gives to botanical study the 

 attractiveness which attaches to all life histories. 



The lecturer next passed to new views acquired in regard to 

 the structure of these plants. Everbody knows that plants are 

 composed of myriads of minute compartments, different in shape 

 and office, which are so combined as to make the organs and con- 

 stitute the pUmt. In these compartments resides the living 

 matter or the protoplasm, in which all life is manifested. Up to 

 about fifteen years ago, it was held, on what was believed to be 

 satisfactory evidence, that the living matter in each one of these 

 cells or compartments, Avas quite separate from the living matter ia 



