SACBKOOD. 



21 



plainly visible. The margin frequently presents a wavy outline cor- 

 responding to the original furrows and ridges of the lateral margin of 

 the larva. 



Posterior third. — The posterior third (figs. 23 and 24) extends upon 

 the bottom of the cell, but does not completely cover it. A lateral 

 view of the scale (fig. 24) shows that it is turned upward anteriorly 

 and drawn somewhat toward the bottom of the cell. The ventral 

 surface is concave, often roughened, and directed somewhat forward. 

 This margin, hke that of the middle third, has a tendency toward 

 beiag irregular. 



The scale. — The scale can easily be removed intact from the cell. 

 (PI. II, X.) Indeed, when very dry, many of them can be shaken 

 from the brood comb. When out of the ceU, they vary markedly 

 in appearance. The anterior third is of a deeper brown than the 

 the other two thirds as a rule. The dorsal side of the middle and 



Fig. 24. — Scale, or larval remains, in position in cell cut lengthwise, lateral view. (Original.) 



posterior thirds is shaped to conform to the floor of the cell, being in 

 general convex, with a surface that is smooth and polished. The 

 margin is thin and wavy. The anterior third and the lateral sides of 

 the middle and posterior thirds being turned upward, the ventral sur- 

 face being concave, and the posterior side being convex, the scale in 

 general presents a boathke appearance and could be styled "gondola- 

 shaped." This general form of the scale has been referred to by 

 beekeepers as being that of a Chinaman's shoe. When completely 

 dry, the scale is brittle and may easUy be ground to a powder. 



Corvd%ti/)n of the virus in the scale.-^The scales in sacbrood, when fed 

 to healthy bees, have shown no evid(^nce of being infectious. 



llio length (jf time that dead larvsB ar(^ p(^rmitted by the hoos 

 to r(!main in the cells before thc^y ar(^ removed varies. They may bo 

 removed soon aft(^r death, they may remain until or after they have 

 ])Cforn«' a dry scale, (>r they may be n'moved at niiy iiitcrvc^ning stage 

 in tlicir <lec.ay. Not inrnqiicndy lliey are permitted to remain to oi* 



