1895 THE MICROSCOPE lOl 



How the Change in Color in Petals Takes Place. 

 Keeping Notes. The Brownian Movement. 



BY ARTHUR M. EDWARDS, M. D. 



NEWARK, X. J. 



I have been looking over the memoranda of microscopic 

 observations I keep and have kept for over thirty 

 years and find amongst them things that will bear repro- 

 duction now and here. And here, by the way, I wish to 

 recommend the keeping of such a book by everyone who 

 observes nature. It is good to put down everything that 

 you see. Never mind how insignificant the facts seem 

 at the time they are recorded thev may start a train of 

 thought then or in the future that may bear fruit that 

 will ripen into a luscious apple or pear of promise. 

 After years I have found that a recorded fact is valuable 

 and can hitch on to a train that will bear me along to a 

 station I have been aiming at for a long time. The notes 

 can be illustrated, never mind if you cannot draw, an 

 illustration will convey the idea that you want better 

 than a whole page of letter press. Colored illustrations 

 are necessary many times and I color them at the time. 

 Another color may supervene and another colored illus- 

 tratioQ will be necessary. Never mind how much labor 

 it requires. It will tell. 



I was reminded of that when I was looking over some 

 notes of mine made in May 1867. They were on the ex- 

 amination of the petals of Weigelia rosea the beautiful 

 colored china flower that we have so common in our 

 gardens. The petals are some of them rose colored and 

 some of them white or nearly so. And I wondered why 

 the petals were rose colored when they open and always 

 change to a lighter tint before they fade. I split a petal 

 in two and put it in water on the stage of my microscope 

 and viewed it by means of a i inch objective and a 1 inch 



