4 BULLETIN 810, U. S. DEPAETJIEXT OF AGKICTJLTITKE. 



area along the dorsal median line extending nearly the length of the 

 body. The contents of the stomach may be seen through this area. 

 The color of the mass is due chiefly to the presence of pollen. It is 

 usually some shade of yellow. The median area presents in its 

 appearance a sharp contrast to the bluish-white, opaque portions on 

 either side of it. Similar appearances are to be noted in the larvae of 

 Group 1. 



The larva removed from the cell performs only slight movements, 

 lies partly coiled, and is more or less turgid. The segments are promi- 

 nent. When the body wall is torn there flows from the ruptured wall 

 the clear larval blood, in which are suspended often fat and other 

 tissue cells which give to it a somewhat milky appearance. The 

 stomach, a transparent tube easily torn into segments, contains a 

 mass of partially digested food, pollen constituting usually a con- 

 spicuous portion of it. 



GROUP 3 



Group 3 consists of capped larvae. These are, therefore, larger than 

 those described in Groups 1 and 2. In the group are included the 

 larvae which have spun a cocoon as well as those which have not. An 

 endwise position in the cell may or may not have been assumed. The 

 larvae are seen in various positions. Not infrequently some portion 

 of the dorsal surface is turned toward the observer, the narrow, me- 

 dian, transparent area being in evidence as iix younger larvae. Healthy 

 larvae occupying an endwise position are described in papers on sac- 

 brood and American foulbrood (17, 19) and will not be referred to 

 further at this time. 



SYMPTOMS 



In European foulbrood, as in other brood diseases, the colony as 

 a whole and not the individual bee should be considered as the unit in 

 the discussion of the symptoms of the disease. The description of the 

 symptoms recorded in the present paper is based chiefly upon observa- 

 tions made on the disease produced through artificial inoculations. 

 In making the studies in the experimental apiary observations made 

 by beekeepers have been duplicated and new facts determined. It 

 has been possible also to locate errors which have been made in 

 discussions of symptoms of the disease. 



GENERAL SYMPTOMS FROM A CASUAL EXAMINATION 



Death of brood during the feeding stage, in uncapped cells, is a 

 characteristic of European foulbrood. The brood nest in the disease 

 usually presents an irregular appearance, capped cells and uncapped 

 ones being found scattered irregularly over the brood frames, giving 

 to them the " pepper box " appearance (PI. I) often referred to by 



