METHODS 21 



The young anthcridium arises very near the apex of the thallui. as a 

 r large cell, projecting from the *idc of the midrib (Fig. 10. A). 

 ^ion wa and separates a basal cell which 



takes no part in the development i the antheridium itodf, and an outer 



i he real mother :>c anthcridium ( 1 ig 10 



about the same time that tin* transverse division is formed in the 

 ridium. certain neighboring superficial cells of the midrib 



>pccial structures accompanying the anthe 



Some of : ompanion cells" secrete the mucilage which bathes the 



.; anther t always readily distinguishable from 



tages of the anthcridia themselves, finally develop into the 

 chara scales covering the older .nit <>mcwhat as des< 



by Campbell [ 1 1 for Am 



m the antheridium show some variation. Of the two 



crll- formed by the first transverse wall, the inner one divides by a verti- 



ill into two cells, which remain sunk in the midrib and usually divide 



; Dually be recognized at the base of 

 talk in the fully developed anthcridium. 



The first wall in the antheridiur > also transverse. Of the 



two cells tluis formed, the lower gives rise to the stalk of the antheridium. 

 and also t< or of cells separat jierm-cells from the stalk of the 



anthcridium. The outermost of the two original cells divides first by a 

 tl wall, and each of these < \t divided by a nearly peri- 



clinal wall into two very unequal cells. This wall intersects both the out- 

 side wall of the antheridium and the median wall, and is quickly followed 

 by a tnilar wall which irect* the fir-t one and also intersects the 



all A of the antheridium at this stage ( Fig 1 i. 



> triangular central cells surrounded by four narrow per- 

 ipheral ones. <wng antheridium at thi< stage closely resembles 

 that of Porclla Bolam npbt-11 (i |. Fig. 52). and differs from the 

 type of the Jun^crmanniales. where, according to I-ritgeb ((l). II. 

 p. 44) these two peripheral cells do not extend to the top of the anther- 

 idium. and a third peripheral cell is cut off before the separation of the 

 central cell is en- The appearance of longitudinal sections of the 

 theridium. cut respectively in the plane of the first median wall. 

 and at right a 10. D. G. /:. //. Cross-sections 

 nlar stages are shown b I. C. The next divisions take 

 in the peripheral cells, and in the stalk, the two primary spermato- 

 gcnous crIU remaining undivided until the stalk is well developed and 



