104 MOSSES WITH A HAND-LENS 



in moist woods everywhere, growing, sometimes on the soil, 

 sometimes on rotten wood. The capsules mature in May, but 

 can be found in recognizable condition until August. 



M. AFFINE CIUARE (Grev.) C. M., the Toothed Mnium, closely 

 resembles the Woodsy Mnium in many respects, but is easily dis- 

 tinguished by the leaves. The leaves of the Toothed Mnium are 

 serrate with very long and slender teeth, which extend to the 

 base of the leaf. In the Woodsy Mnium the leaves are serrate 

 with shorter teeth that do not extend much below the middle of 

 the leaf. Until one has had some practice, it may be necessary to 

 mount the leaves in order to see the serration plainly. No reliance 

 should be placed on the shape of the leaves in distinguishing 

 these two species, as the leaves vary greatly in shape in different 

 plants and on different parts of the same plant. 



M. AFFINE Bland. The common form of this species is the 

 variety described above. The species is rather rare and is a 

 puzzling form for the hand-lens student. The figures and 

 description of M. Drummondii in the FIRST EDITION were based 

 on this species largely. It has the capsules clustered, and teeth 

 on the margins of the leaves shorter than in the Toothed Mnium. 

 It is distinguished from M. Drummondii by the longer, less 

 decurrent leaves, absence of creeping stems, and by having an- 

 theridia and archegonia on separate plants. The male heads 

 bearing antheridia can usually be found mixed with the plants 

 bearing capsules. 



M. DRUMMONDII B. & S.,the true Drummond's Mnium, is so 

 infrequent as not to require a treatment here. It is distinguished 

 from M. affine by the characters given under that species. By 

 carefully stripping off the perichsetial leaves and mounting 

 them and the seta on a slide the presence of antheridia can 

 usually be made out with a high power lens. 



M. SPINULOSUM B. & S., the Red-mouthed Mnium, is a third 

 species somewhat resembling the Woodsy Mnium and growing 

 in similar situations, but less common and usually growing in 

 woods. The peristome is a very bright red-brown, and after the 

 operculum has fallen it makes a very conspicuous red band about 

 the mouth of the yellowish-white capsule. If the leaves of the 

 Red-mouthed Mnium be carefully studied, the teeth on the mar- 

 gins will be seen to be in pairs. To see this with a hand-lens 

 requires considerable care, as the teeth are small and hide one 

 another. The capsules mature at least two weeks later than 



