14 BULLETIN 671, U. S. DEPAKTMENT OF AGRICULTUEE. 



MICROSCOPIC FINDINGS. 



The bees if alive may be killed easily by crushing the thorax be- 

 tween the jaws of a pair of dissecting forceps. Then the thorax is 

 grasped by the thumb and finger of one hand, the tip of the abdomen 

 is grasped with a pair of forceps held in the other, and by gentle 

 traction the ventriculus (stomach) and hind gut usually come away 

 entirely and may be teased apart for examination, or the whole gut 

 may be crushed under a cover glass and examined. In making a 

 diagnosis at least 10 bees should be examined. Spores of Nosema 

 apis if present are easily recognized, being oval, highly refractile 

 bodies (PI. II, fig. 2). Usually they occur in large numbers crowd- 

 ing the field. They stain with difficulty, and for diagnostic pur- 

 poses water mounts unstained are satisfactory. The young forms 

 of the parasite when present are quite difficult of detection, and 

 should not be depended upon in the diagnosis. 



Occasionally protozoa other than Nosema apis have been en- 

 countered in the examination of adult bees. These have no relation 

 to Nosema disease, however, and may be disregarded in its diagnosis. 



LITERATURE. 



Much has already been written on bee diseases. The journals on 

 beekeeping contain numerous articles pertaining to them. Bulletin 

 No. 98 of the Bureau of Entomology briefly reviews a number of 

 papers, published prior to 1912, dealing with the causes of these 

 diseases. The papers reviewed and the publications cited, together 

 with the papers in the following list and the references which they 

 contain, comprise a fairly comprehensive resume of all the literature 

 detailing work done on these diseases. 



With regard to further papers to appear soon, it is announced 

 that studies have been made on American foulbrood and European 

 foulbrood similar to those on sacbrood (White, 1917) and Nosema 

 disease (White, 1918) and that the results are now being prepared 

 for publication. 



Anderson, John, and Rennie, John. 



1916. Observations and experiments bearing on " Isle of Wight " disease 

 in hive bees. In Proc. Roy. Phys. Soc. Edinb., Session 1915-1916, v. 20, 

 pt. 1, p. 23-61, 1 pi. 



Aristotle. (B. C. 384-322.) 



1783. Histoire des Animaux d'Aristote avec la Traduction Frangoise (Notes 

 sur l'Histoire des Animaux d'Aristote) par M. Camus [Greek and French 

 on opposite pages]. Paris. 2v. 4°. 

 Volume 1, Book IX, page 615 : Bee diseases. 



1910. The works of Aristotle Translated into English under the Editorship 

 of J. A. Smith [and] W. D. Ross. Oxford, v. 4, Historia animalium by 

 D'Arcy Wentworth Thompson. 

 Book IX, p. 626b : Bee diseases. 



