MOSSES WITH A HAND-LENS 



187 



FIG. 2. 



Acumen, the gradually tapering narrow 

 point of an acuminate leaf. (Fig. 2, b.) 



Acuminate, a term usually applied to 

 leaves that gradually taper to a narrow 

 point. A few recent writers use the term as 

 applying only to those leaves that are not 

 uniformly narrow and limit the term acu- 

 men to that part of the apex beyond the 

 point where the narrowing begins to be less 

 abrupt. According to those authors a leaf 

 uniformly narrowed would not be acumi- 

 nate, no matter how slender the apex. The 

 author has followed this usage to some extent in previous writ- 

 ings, but general usage does not seem to sanction this restriction 

 of the term. 



Acumination. See acumen and acuminate. 

 Acute, with a sharp point, shorter than acuminate. 

 Aggregate, clustered ; usually applied to two or more sporo- 

 phytes from one perichastium. 



Alar cells, the cells at basal angles of the leaf, commonly dif- 

 ferent from cells of the main part of the leaf, being shorter and 

 often nearly square, or inflated and hyaline, and 

 often highly colored. (Fig. 3.) 



Amphigastria, the third row of leaves 

 found on the under side of the stems of the 

 Hepatic ae. 



Angular cells. See Alar cells. 

 Antical, applied to that surface of the 

 stems of hepatics which is uppermost when 

 the stems are prostrate. 



Antheridium, the male reproductive organ con- 

 taining the antherozoids. (Fig. 4.) 



Anther ozoid, the small flagellate male cell which 

 escapes from the antheridium, and in wet weather 

 swims to the archegonium and down its neck to the 

 egg-cell in the bottom. 



Apical cells, the cells composing the apex of the 

 leaf. They are often broader and shorter than the 

 cells of the middle of the leaf. 



Apophysis. See hypophysis, the more correct term accord- 

 ing to Braithwaite. 



FIG. 4. 



