Journal of 



Applied Microscopy. 



Volume I. 



OCTOBER, 1898. 



Number 10 



Microscopic Work in Large Classes. 



One of the great difficulties which 

 confronts the science teacher in a city 

 high school, is the large size of the 

 classes. 



The New York High School for Boys 

 and Girls is occupying for the present a 

 former grammar school building. The 

 physiology laboratory is a room 20x22 

 feet. Along one side, lighted by two east 

 windows, is a row of tables which pro- 

 vide space for six to ten compound mi- 

 croscopes. In the remaining limited 

 space of the room four rows of single 

 desks accommodate twenty-four pupils. 

 Our classes number thirty-six to forty. 

 Two of the aisles are provided with 

 chairs for the extra pupils. The students 

 are thus crowded into two solid masses, 

 leaving a central aisle and an aisle at 

 each side. In spite of these difflculties, 

 however, laboratory work has been done 

 in class thoughout the year, and the mi- 

 croscope has been almost constantly in 

 use. 



Our equipment for microscopic work in 

 botany, zoology, and physiology is the 

 following: Twenty-four compound mi- 

 croscopes, each provided with coarse and 

 fine adjustment, double nosepiece, two- 

 thirds inch and one-sixth inch objectives, 

 and two inch and one inch eyepieces: six 

 sets of physiological slides; paraffln bath; 

 Minot microtome; stains and reagents. 



Two periods per week throughout the 

 year are assigned to the subject of phy- 

 siology in our course of study. The first 

 exercises of the year are devoted to the 

 study of the parts and the use of the 

 compound microscope. Each pupil 

 makes a drawing of the instrument, la- 

 beled in detail. In a Laboratory Man- 

 ual of Anatomy and Physiology, pre- 

 pared for our high school classes, pub- 

 lished by Henry Holt & Co., is a list of 

 rules for the use of the low and high- 

 power objectives, and a statement of the 



magnifying power of various combina- 

 tions of objectives and eyepieces. Each 

 pupil learns these rules and applies them 

 at the microscope. 



The method pursued in the study of the 

 blood is typical of the work of the 

 course. Six compound microscopes are 

 placed in position on the tables, and a 

 slide of amphibian corpuscles (double 

 stained and mounted in balsam) is placed 

 in focus beneath the high-power objec- 

 tive of each instrument. The pupil takes 

 to the microscope his note-book, a pencil, 

 and the following laboratory directions: 



Microscopic Study of Corpuscles of 

 Frog's blood: 



1. How many distinct types of solid 

 bodies (corpuscles) can you see in the 

 frog's blood? 



2. Is there any variation in the form 

 or size of different corpuscles of the 

 same type? 



3. Draw two corpuscles (differing as 

 much as possible) of each type, much 

 enlarged, labeling nucleus and cell body. 



The drawings are made on a page in 

 the note-book while the pupil is at the 

 microscope; the answers to the questions 

 are written as soon as he has taken his 

 seat. Each drawing is submitted to the 

 instructor as soon as completed, for sug- 

 gestion or criticism, and when important 

 structures have not been represented the 

 pupil returns to the microscope for fur- 

 ther study. Twenty to thirty minutes 

 suffice for each pupil in a class of thirty- 

 six to make a satisfactory drawing of the 

 corpuscles. 



As a means of correcting false observa- 

 tions and of suggesting further points 

 of instruction, photo-micrographs of 

 similar corpuscles are distributed, which 

 the pupil compares with his own draw- 

 ings. 



Having completed the study of the 

 frog's corpuscles, a comparison with hu- 



