634 On the Compass Plant [August, 



the prairies in which this plant abounds. The account was some- 

 what discredited at the time by the observation that the plants 

 cultivated in the Botanical Garden at Cambridge, U..S., did not 

 distinctly exhibit this tendency.'" 1 



Nature for Feb. r, 1877, contains the first of a series of articles 

 by " A. W. B." on " Remarkable Plants," and begins with the 

 compass plant as No. I. It says: "Our illustration is taken 

 partly froai the plate in Jacquin's ' Ectogae,' the only good draw- 

 ing of the plant published, assisted by comparison with dried 

 specimens in the Kaw Herbarium." The full title 2 of Jacquin's 

 book, published in Latin in Vienna in, 18 12, is, " Selections of 

 rare and little-known plants, described from living plants with, col- 

 ored illustrations." Like the plant in Upsala, Sweden, in 17S1, it 

 was cultivated, but its true rarity, and its claims for interest and 

 investigation, were quite unknown. 



If it is asked what remains for the observation of scientists in 

 this connection, we answer, that besides the occasional torsion of 

 90° referred to by Dr. Gray, and the exceptions to the rule in 

 which the whole leaf is east and west, to which we have briefly 

 alluded, we wilt add : the whole subject of the reason (the entire 

 rationale) of leaves turning towards the light is worthy of more 

 full experiment and elucidation. 



I had written the above sentence when I was pleased to see in 

 the American Journal of Science for March, 1882, a communica- 

 tion by Dr. Asa Gray, stating the substance of a paper by Fran- 

 cis Darwin, in Journal of the Linnsan Society, 188 1, "On the 

 power possessed by leaves of placing themselves at right angles 

 to the direction of incident light." Dr. Gray concludes his 

 abstract by saying : "The experiments varied in many ways, and 

 with arrangements to eliminate epinastic and hyponastic ten- 

 1 Dr. Gray adds : "The lines in * Evangeline' were inspired by a personal com- 

 1847. Sir Joseph Hooker adds in a note after quoting the lines, « I cannot congrat- 



