I893-] 



GALL MITES 



251 



specimens. Would you care to have some galls of the 

 Phytoptus rib is from black currant in their (I think) very 

 unusually advanced condition for this time of year ? If so, 

 I think I could procure some from Kent. 



It is with regret that I read in your letter that you are not 

 in strong health. But if you could work less severely might 

 not you hope to have benefit ? The excessively minute work 



i, Mite, greatly magnified natural length of female 0^23 millimetres ; 

 2, head and fore parts, still more magnified (by permission, after 

 Dr. A. Nalepa) ; 3, mite-galls of unusually large size, with one withered 

 and open. 



FIG. 65. CURRANT GALL MITE, PHYTOPTUS RIBIS, NALEPA. 



of your elaborate investigations must be exceedingly wear- 

 ing. In my own observations (which, indeed, are not to be 

 compared with yours) I always find they tell very much on 

 my health if I have at once to overwork my sight with the 

 microscope and my mind in the record of my observations. 



