194 HELEN L. M. PIXELL-GOODRICH. 



experiments on the infectiousness of this disease. On no 

 occasion have I been able to obtain any bacteria from the 

 blood, muscles or fat body of bees examined bacteriologically. 

 Prom the alimentary canal so vast is the number of bacterial 

 colonies usually obtained with ordinary nutrient media that 

 the difficulty is to separate them for identification.^ No 

 organisms have so far been demonstrated actually inside the 

 cells of the alimentary canal although I have stained numerous 

 serial sections with almost every conceivable stain, including 

 Gram, Van Gieson, Claudius, etc. As might be expected, the 

 intestines of bees from almost every different locality contain 

 different bacteria which will grow on various media, some 

 aerobically, others anaerobically. So long as I was uncertain 

 whether a crawling bee was merely senescent or really diseased, 

 the problem of finding whether any special bacterium was 

 associated with the disease was practically impossible to 

 solve. 



The possibility of determining the age of bees is likely to 

 be of further importance in estimating the chances of survival 

 of a stock during the winter. There is no doubt that age and 

 suitable general conditions of life have much to do with 

 successful wintering, and that loss of stock owing to lack of 

 these conditions is often quite wrongly attributed to disease. 



Being then convinced of the necessity of being able to 

 determine the age of a bee, I carefully examined, in the first 

 place, such exterior parts of the body as the hairs, glossa, 

 gonapophyses, etc. On concluding that nothing definite was 

 to be determined from these, the study of the brain and head 

 glands was begun. 



The work of Minot (15) and others, together with the fact 

 that a bee appears to work incessantly dm'ing its short life, 

 suggested that the nerve-cells would give a good indication 

 of age. The results so far obtained show that a. great deal 

 may be learnt from a study of the brain and glands of the 

 head. 



