GEMMAE 3 1 1 



physes. The gemmae are two or three layers in thickness in 

 the central region and one at the margin. Two to eight cells in 

 the portions near the margin are seen to be thin-walled with the 

 outer membranes convex, constituting the nematogones, or cells 

 active in propagation. Although gemmae are produced through- 

 out the year yet none may be found on the material collected. 

 In this case allow the moss to grow for a few weeks in the moist 

 chamber and examine again. When found detach a number, and 



FIG. 145. Gemmae of various Muscineae. I, Marchantla polymorpha with cups 

 containing gemma. 2, longitudinal section through cup of Marchantia. 3, gemma 

 of Marchantia. 4, Tetraphis pellucida. 5, stem of Tetr aphis bearing a cup con- 

 taining gemmae. 6, longitudinal section of cup of Tetraphis showing gemmae. 7, 

 8, single gemmae of Tetraphis. 9, stem of Sciuroides with brood-bodies. 10, single 

 brood- body of Leucodon. II, development of brood-body on rhizoids thrown out by 

 a leaf of Campylopus fragilis . 12, 13, 14, stages in the development of gemmae from 

 apex of leaf of Syrrhopoden scaber. 15, Aulacomnion androgynum. 1 6, stalk of 

 Aulacomnion bearing brood-bodies. 17, 1 8, single gemmae of Aulacomnion. After 

 Kerner. 



