353 



THE PRESIDENT'S ADDRESS. 



THE USE OF MICROSCOPICAL CHARACTERS IN 

 THE SYSTEMATIC STUDY OF THE HIGHER PLANTS. 



By a. B. Eendle, MA., D.Sc, F.R.S. 



Keeper of Botany, British Museum {Natural History). 

 {Delivered February I2th, 1918.) 



The study of microscopic organisms is one in which members of 

 the Quekett Club are so well versed that it is unnecessary to refer 

 to the value of the microscope in the systematic discrimination 

 of their families, genera and species ; many of the objects of your 

 study are recognisable only under a fairly high power. Even in 

 those groups of the lower plants where the individual attains a 

 considerable size the characters which are regarded as of value 

 for the determination of its systematic position enjoin the use of 

 the microscope. Seaweeds cannot be studied apart from the 

 microscope ; and the determination even of the larger Fungi 

 becomes merely a question of matching unless minute characters, 

 such as those associated with the spore, are studied. 



You cannot get very far in the study of Lichens without the 

 microscopic examination of a section ; and the description of a 

 genus, or even of a species, is not now considered complete without 

 reference to the number, shape, size or special characters of tha 

 spores. 



In the study of Mosses " the cells of which the lamina of the-^. 

 leaf consists furnish characters of the greatest importance both 

 on account of the ease with which they can be observed and their- 

 high degree of constancy ' ' — to quote the author of that excellent . 

 guide to the study of British mosses, Mr. H. G. Jameson. 



The Ferns are eminently macroscopic plants, but an examina- 

 tion of the frond does not carry us far, and even for the recognition, 

 of the larger groups an examination of the structure of thej 

 sporangia is necessary. 



JouRN. Q. M. C, Series II.— No. 82. 2? 



