308 THE JOURNAL OF BOTANY 



described, which were common (in varying degrees) to all the 

 capsules, there were additional sporadic abnormalities indicative 

 of disturbance of the ordinary processes of development. One 

 capsule at least had a peristome in which the teeth were greatly 

 extended into long, filiform, nodose tips, resembling the cilia of a 

 Bryum ; and several had the beak of the operculum abnormally 

 elongated, so as much more than to equal the length of the capsule. 



I sent specimens of the moss to two or three bryologists, and 

 the variety of opinions expressed is at least a testimony to the 

 unusual nature of the phenomenon ! At the same time, it is right 

 to point out that only the more extreme forms were received by 

 these correspondents, who had therefore not the complete material 

 for a conclusion that the later gatherings afforded. 



Mr. W. E. Nicholson, to whom I first sent it, pointed out the 

 objections to the "hybrid" theory, and was incHned to see in it 

 an abnormal condition. Dr. Hagen found the spores rather 

 unequal in size, suggesting a hybrid origin, but other characters 

 did not support this, and he wrote that in his opinion it was " a 

 variety of D. heteromalla analogous to the var. calUstoma of 

 D. varia." Mrs. Britton replied: " It certainly does seem^as if the 

 capsules were more like D. varia than D. heteromalla, though the 

 plants certainly are the latter and resemble the var. interruptum. 

 Mitten had a form much like yours from Surrey, and I have a 

 depauperate form with capsules more typically oblique than 

 yours." Finally, Mr. E. S. Williams wrote: "Looks like a case 

 of the plants being so crowded as to prevent best development of 

 fruit. Near either var. orthophylhcm [? var. orthocarpum — the 

 leaves in most cases at least are normally falcate. — H. N. D.] or 

 interrupttcm." I scarcely think that the density of the plants can 

 be the cause, as Mr. Williams suggests, of the want of develop- 

 ment of the fruit. For one thing, the setae of the previous year, 

 and also those at present developing, show, with the same con- 

 ditions as to density, no variation from the normal. Moreover, I 

 should not consider the plants to be unusually close in their growth. 

 From the little experience I have of North American plants I am 

 inclined to think that D. heteromalla does not often attain there 

 quite such a robust development as is very frequent with us, and 

 what would there be considered an unusually dense and strong 

 growth is quite usual here. Still, it is no doubt the case that the 

 more dense and compact forms are those which fruit the least 

 frequently and least abundantly, though I have supposed that this 

 was due rather to the unfavourable conditions under which such 

 plants usually grow than to the direct influence of their com- 

 pactness. In any case, as I have mentioned above, this scarcely 

 appears to be the cause here. Explained or unexplained, however, 

 it seems sufficiently striking and unusual to be put on record. 



I should perhaps have remarked that, though in the more or 

 less erect and symmetrical capsule our plant comes near the var. 

 orthocarpa (Hedw.), the character of the seta and other considera- 

 tions preclude its being placed under that variety. 



I may add that I hope to distribute specimens through the 

 Moss Exchange Club this winter. 



