The Microscope. 77 



THE WOEKING SESSION. 



ALBERT MCCALLA, PH. D. 



IN a former communication I presented some reasons for re- 

 garding the Working Session as a very important part of the 

 meetings of our National Society, and for hoping that it may be 

 given a full and prominent place in the future meetings. It 

 may not be amiss to add some further thoughts in its favor. 



First, then, the Working Session is one in which all the 

 members of the Society can meet on common ground. It is 

 true they seem to stand in two distinct classes, experts and 

 learners — but this is only an apparent and temporary distinc- 

 tion. All are together students of microscopic technique, com- 

 paring with and communicating to each other the advances 

 they have made, the methods they have tested and those they 

 wish to learn. Workers each in different fields, the subjects of 

 their study are often so diverse that members of such a society 

 sometimes feel but little interest in the results of each others 

 investigations, or only that general interest which they have in 

 all discovery. The diatomist cares but little for the minutiee of 

 the nerve termini in the lungs; the practical physician, per- 

 haps, votes the carefully written paper on the resolvability of 

 diamond-ruled lines a bore ; and the mineralogist gives atten- 

 tion to the botanists discussion of the evolution of the laticif- 

 erous tissue of the dandelion chiefly out of courtesy. But each 

 one is deeply interested in the methods of work by which such 

 results were obtained, and is anxious to learn all the latest dis- 

 coveries in technique, all the niceties of preparation of the ob- 

 jects and manipulation of instruments, that he may turn them 

 to account in his own work. Each microscopist is, or ought to 

 be, able to verify his tools, able to test and calibrate — so to 

 speak — his objectives and other apparatus, to measure accurate- 

 ly their aperture, amplification, and the accuracy of their cor- 

 rections. Each one wishes to learn the practical details of any 

 promising method of preparation, mounting or examination of 

 objects — and all this can be but learned by actual observation 

 of how acknowledged experts do it. 



Again, it should be remembered that while some are so 

 fortunate as to live in large cities and enjoy the benefits of 



