Microscopy at Ruhleben. 27 



of winter here are extreme. "With inadequate heating it is im- 

 possible to carry on the necessary work of embedding and cutting 

 with the microtome. Without knowing these facts the account of 

 the equipment of the laboratory might conjure up a view of semi- 

 luxuriance. 



These men are living under most depressing conditions, and it 

 is only due to a dogged determination to weather the storm that 

 any scientific work is systematically carried on. 



Lettek from Dk. a. Eckley Lechmere to E. Paulson, F.K.M.S., 



DATED August 14, 1917. 



I am very pleased to supply further information as regards the 

 microscopical equipment. When the laboratory started in the 

 spring of 1915, we were fortunate enough to have several micro- 

 scopes at our disposal. These were supplied by people in the 

 Cam^ who had their instruments in Germany, I had been work- 

 ing at plant diseases in Munich with Prof, von Tubeuf, and at the 

 cytology of sex in insects with Dr. Biichner, so I was fortunate in 

 having both instruments and a certain amount of material at hand 

 which Prof, von Tubeuf kindly sent me here. Since then several 

 more instruments have been obtained by other students. We 

 have now an excellent microscopical outfit for general laboratory 

 work. The instruments include the foUowius; items : — 



One Leitz binocular, two Leitz C, two Leitz GH, two Winkel, 

 one Seibert, and one Nietsch, one Baker Diagnostic, and a set of 

 eight dissecting lenses, two polariscopes, micrometer eye-pieces,, 

 camera lucida and microspectroscope, one Leitz Minot microtome. 



For sitting accommodation we use a large deep bench, fitted 

 under the windows in the w^all of the loft. The windows them- 

 selves have been much enlarged, and this year w^e have had sky- 

 lights let into the roof. For work in the evenings I have arranged 

 a small transformer to work from the main electric supply, which 

 gives sufficient current to run twenty 4-volt lamps ; at the same 

 time it can supply current for heating a small drying- box for the 

 microtome slides, and is further used for an electric needle for 

 orientation of sections in wax. 



The general instruction in laboratory work and the preparation 

 of lectures do not leave much time for original work. The only 

 things I have attempted here have been a series of stages in the 

 development of the Orange Scale Insect {Aspiclotas), and a few 

 preparations of a curious mite infesting the earwig. The body of 

 each mite has a long stalk which forms a branchincr meshwork 

 gradually covering the body of the host. I have never seen it 

 before, and do not know the genus. During the months of May 

 and June this year I kept a series of eggs of Limnxa stagnalis. 



