92 PEOCEEDINGS OF THE ACADEMY OF [ISBS^- 



V. VIOLA IN RELATION TO POLLINIZATION AND FECUNDATION, 



Though it has beeu shown by many close observers that the 

 general opinion is erroneous that early or perfect flowers of many 

 species of Viola are infertile, the impression is still widely preva- 

 lent, especially in the case of the very common Viola cucullata. I 

 have myself held that opinion, though I have placed on record that 

 Ihey were abundantly fertile wdien growing on a dry rocky piece of 

 ground. I had, however, never made the continuous daily obser- 

 vations on them that I have made on other plants, and so made it 

 a point to do so, commencing the task on the first of April, 1897. 



I have an orchard of about half an acre, partially shaded by 

 the branches of the apple trees meeting together. The surface was 

 originally in grass, but at the date given only a few tufts remained. 

 The wdiole at the date named was a sheet of violets in bloom. 

 These many thousands of plants all sprung from a few. I noticed 

 these a quarter of a century ago. Myriads of seeds from last 

 year's crop were showing cot3dedons. By sheer force of numbers 

 they were crowding out all other vegetation, and it is a question 

 whether their operations had not as much to do with the destruction 

 of the original grass as the shade which the apple trees afl^orded. 



Though from a few original plants, the assemblage at this date 

 presented a remarkable variation in the form and color of the flow- 

 ers. Some had petals almost linear, others petals almost round. 

 In some cases the two upper petals would be nearly round, and the 

 three lower ones very narrow. The color of the petals varied in 

 innumerable shades, from the normal violet to nearly white in one 

 directi(>n, and to nearly red in the other. Some plants would have 

 the peduncles little longer than the leaves ; others would have the 

 flowers on long and slender peduncles. A notable fact, however, 

 was, that with all this variation in the flowers, not a trace of varia- 

 tion could be found in the plants themselves. In foliage and 

 habit, every plant seemed an exact repetition of another one. As 

 conditions of environment could have nothing to do with these 

 variations, and as there were no varieties to aid variation through 

 cross pollination, there can be but one deduction, that internal 

 energy alone is responsible for the changes. 



My next thought was to Avatch for insect visitors. Winged 

 insects are scarce with us in April. I saw none among these planta 



