And grows even after the spores are ripe. The neck of the capsule is swollen 

 into a hypophysis much larger than the capsule itself; size, shape and color of 

 this hypophysis are variable, but characteristic for each species. In all cases, 

 however, the hypophysis becomes bright colored about the time the spores are 

 ripe, but even thereafter it continues to grow for a time, so that the plant be- 

 comes larger and showier the longer it lives. The capsule and its peristome are 

 very hygroscopic; its central columella is widened at the tip into a small disk. 

 When the capsule is ripe, the operculum falls off and, in dry weather, the teeth 

 of the peristome curve outward over the margin of the capsule, which shrivels 

 and contracts, while the columella extends beyond the rim. The spores are thus 

 pushed upward along the columella against its terminal disk, and drop partly 

 outside the capsule on the expanded teeth of the peristome. Most other moss 

 spores are dry and powdery, and easily transported by the wind, but in Splach- 

 num they are sticky and form small clusters which remain attached between the 

 columella and margins of the capsule and also on the expanded peristome. 

 They are thus freely exposed and ready to adhere to any part of a fly that may 

 pass over them. In a moist atmosphere the capsule swells again to its former 

 shape and size, and takes the spores back into its cavity, while the teeth of 

 the peristome fold back to close the mouth of the capsule as with a lid, so that 

 rain or dew can not wash the spores away and rob the plant of their use. 



In Tetraplodon the hypophysis is not so bright colored, but here too, it 

 continues to grow after the spores are ripe; the seta of mature capsules, however, 

 does not grow further. These mosses being perennial, their cushions become 

 much larger and showier than those of Splachnum, The columella is crowned 

 with the detached tips of the peristomial teeth, but does not extend beyond the 

 margin of the shriveled capsule. Since the seta is shorter and often also thicker 

 and stiffer than in Splachnum, it can support larger insects, such as blow-flies. 



From my own observations and those of Bryhn we may conclude that 

 many, if not all, SplachnacecE are adapted to having their spores scattered by 

 flies. In the first place the various members of the family are found growing 

 only on decaying organic substances, such as excrement and dead bodies. As 

 shown experimentally by Bryhn, their spores do not germinate on other sub- 

 strata. Excrement and dead bodies, however, are comparatively scarce in 

 nature, always considerably scattered over a wide territory, and often hidden 

 in crevices. If, as in other mosses, the spores of the SplachnacecE were carried 

 by the wind, they would have but little chance of reaching the proper substra- 

 tum. That they are not transported in this way is further shown by their stick- 

 iness. They adhere readily, however, to the muscid and anthomyid flies which 

 are constant visitors both to the fructifications of these mosses and to dung and 

 carrion. 



Bryhn is still uncertain as to the manner in which the flies are attracted to 

 the moss. He supposes that the beautiful cushions may serve as a "play- 

 ground" for them, or as resting places between flights. "Most probably," he 

 continues, "the flies are deceived by the bright colors and suppose that the 



