83 



M5RARY 



Roots and Some Growths Upon Them. 



By E. B. Green, F.R.M.S. 



(Bead April 19th, 1895.) 



Plate V. 



The drawings upon the table are intended to represent the 

 structure and rate of growth of some roots. 



Root hairs drawn to a uniform scale ot 100 diameters, and 



Parasitical and other growths, which I have found upon them. 



The seeds of a large number of plants were sown in pots filled 

 with light soil, and put into a warm greenhouse, where the 

 temperature varied from 45° to 70°, and the seedling plants were 

 from time to time carefully taken up with a sufficient quantity of 

 adherent soil, plunged into a tank of water, and after gentle 

 washing floated on to a sheet of glass, or (if intended for micro- 

 scopic examination) upon a glass slide rather larger than the 

 ordinary size, and a covering glass was put on before the slide was 

 removed from the water, care being taken to exclude air bubbles. 



The specimen was put upon the stage of the microscope as soon 

 as the outside of the covering glass was dry, and it was also 

 examined when the specimen had dried. I found this double 

 examination necessary, as some of the more delicate organisms 

 which could be plainly made out when first put upon the slide lost 

 all their characteristic form and structure when they became dry, 

 whilst others which were colourless could not be seen till all the 

 water had evaporated. 



Some of the drawings, showing the rapidity with which roots 

 grow under favourable circumstances, are made the natural size. 



A seed of maize, eight days after planting, produced 20 roots 

 of various lengths ; the longest six inches. Another fourteen 

 days from planting had upwards of 100 roots, and the longest of 

 which was eight inches. A seed of barley produced 70 roots in 

 eight days, and an oat upwards of 400 roots in 48 days ; several of 

 them were more than fourteen inches long, and all these roots 

 were densely covered with root hairs. 



