—30— 



The abundance of capsules, the apparently constant absence of D. varia 

 in association, and the great quantity of the male plant of D. heteromalla pre- 

 sent, made it pretty clear that the hybrid theory must be abandoned, and some 

 other explanation sought. Thi^ was confirmed and indeed demonstrated by 

 some of the later gatherings sent me by Mr. Hurst. For not only did many 

 intermediate forms occur between the extreme form as described above and 

 normal heteromalla setse and capsules, but on one or two tufts I found, side by 

 side with the abnormal capsules and on the same stems, setae of last year's fruit 

 exhibiting no difference from ordinary heteromalla; while later on, tufts gathered 

 in July presented young setae of the present year which were evidently on the 

 road to become the normal, elongate, pale yellow setae characteristic of the 

 normal plant.* Clearly, therefore, the peculiar capsules represent a state or 

 form merely, and that not so much a local as a temporary state, due, one would 

 suppose, to some climatal conditions. What these may have been, however, 

 I cannot suggest. The abnormal capsules appeared to mature principally about 

 the end of May and early part of June. Midwinter is the usual maturing time 

 for the species, but it varies greatly, and I do not think the simple fact of re- 

 tardation would be itself sufficient to account for the results. The extremely 

 hot and dry April of this year is perhaps the most marked meteorological feature 

 of the fruiting period of the plants in question; but it is evident that, for cap- 

 sules ready for deoperculation in May, the setae must have been fully developed 

 long b<^fore the late spring of this year, and as the most, or one of the most, 

 noticeable deviations from the normal is presented by the seta, the cause must 

 be looked for at some far earlier stage. The setse of next y'i'ar's capsules were 

 showing well above the shoots when gathered in early July this summer, and if 

 the plants were in a similar stage of development last July, the suggestion may 

 be hazarded that the extreme heat and drought of that period of 191 1 may have 

 been the predisposing cause, followed by an arrest of developmenc which only 

 allowed of maturing late this spring. 



I scarcely think that the density of the plants can be the cause, as Mr. R. S. 

 Williams suggests, of the want of development of the fruit. For one thing, the 

 set.T of the previous year, and also those at present developing, show, with the 

 same conditions to density, no variation from the normal. Moreover, I should 

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



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 considerations preclude its being placed under 

 that variety. 



* Since the above was in type I have received further specimens from Mr. Hurst, gathered' 

 on Burridge Heath, in abundant and quite normal fruit of the present year, and still retaining, 

 many of the abnormal capsules here described. 



