6 TASMANIAN BRYOPHYTA, 



least the greater part of its nourishment. The shape of 

 the sporophyte, or, as it is commonly called, the sporogon- 

 ium, will be described under the proper sections, but it al- 

 ways consists of a capsule containing at maturity a mass of 

 spores for dispersal, and is generally borne upon a stalk or 

 seta. 



In most instances the sporogonium has the appearance 

 of a primitive organ that has been developed uj)on the 

 gametophyte for the purpose of propagation, but there are 

 not wanting evidences of reduction. True stomata are pre- 

 sent on the capsules of many mosses, as well as those of 

 Anthoceros, of a similar type to those formed in ferns and 

 higher plants, and in many cases they appear functionless. 

 As such they are more likely to be vestiges left from a vigor- 

 ous, possibly independent, condition than a rudimentary 

 development towards eflBiciency, 



The leaves of mosses are seldom very delicate, and the 

 sporogonium is formed of firm persistent tissue. The hepa- 

 tics may not be leafy, and when these organs are present 

 they are very delicate, easily injured, and the sporogonium 

 is never of firm consistence, often is very fugacious, the seta 

 being pellucid, and the capsule soon bursting into four 

 valves. 



MOSSES. 



Upon germination from the spore the plant first de- 

 velops an elongated filament, the protonema. It consists 

 of very long cells divided by oblique septa. On damp 

 ground Sphagnum produces a flat, broad protonema, very 

 like the prothallus of a fern. Andreaea produces a small 

 tuberous growth from which arise protonemal filaments, 

 which may under suitable conditions grow again into flat 

 plates or cylindric masses. All the other mosses produce 

 filamentous protonemata, which have a superficial resembl- 

 ance to the structure of a filamentous alga. The protonema 

 is commonly short-lived, but it may normally in some 

 species, as, for instance, Ephemerum, be long-lived, and may 

 be induced in other mosses to prolong its life and extent by 

 any circumstance that prevents the development of leafy 

 buds. The typical shoot of the moss plant starts its growth 

 as a lateral bud on the protonema. 



The protonema never bears other organs than the bud, 

 and as it also grows copiously from any part of the plant, 



