OF ARTS AND SCIENCES: JANUARY 9, 1866. 



71 



spects good average specimens. First, a line of ten cells,* arranged in 

 the direction of the diameter, perpendicular to one of the sides, and 

 then two other sets of the same number, similarly arranged in the di- 

 rection of the other two diameters, and crossing the first, were care- 

 fully measured. Three series of such measurements were made from 

 different parts of each comb. The columns marked I., II., III. give 

 the measurements in the direction of the three diameters. 



The greatest aggregate diameter of any one series of ten cells was 

 2.10 inches, and the least 1.85 inches, making a difference of 0.25 

 inch, or the diameter of a cell and a quarter. The average difference 

 is, however, a little less than O.J^O inch. These irregularities do not 

 accumulate beyond a certain amount, and those of one portion are of- 

 ten counteracted in another portion of the same row. In a large 

 piece of comb, sixty cells occupied the space of one foot, which would 

 make the diameter of a cell equal to 0.20 inch ; nevertheless, ten cells 

 taken from either end, and ten taken from the middle of this same 

 comb, when compared, gave marked differences. This correction is 

 not, however, a constant condition, for we have, perhaps in most in- 

 stances, found Hunter's statement correct, viz. that the cells gradually 

 increase in size, the last formed being the largest.f 



* Ten cells were measured, in order to avoid the accumulating error resulting 

 from the measurement of a series of single cells. The error in the measurement of 

 ten cells is no greater than that of measuring one, and divided among the ten 

 becomes inappreciable. 



t Works of John Hunter, Palmer's edition, Vol. IV. p. 436. 



