200 DR. 8. O. LINDBERG ON ZOOPSIS. 
nurse threads spathulate proembryons, from the narrow base of 
which the new individuals are developed. In Andreea we often 
see the spore give rise to a cellular mass from which the usual 
protonema originates ; and in Sphagnacee the product of the ger- 
mination of the spore is a frondose laciniate proembryo formed 
by a single layer of cells, which strongly reminds us of the sterile 
frond of some Liverworts, as of Aneura palmata or Anthoceros punc- 
tatus. Their stem is never frondose, and wants all fibro-vascular 
fascicles, but instead sometimes possesses an axile fascicle of cambii- 
form cells, or even several such (but spread out and not axile) 
in the stem of Polytrichum commune; the stem of. Sphagnacee 
is covered by a proper integument of exoepidermoidal cells in one 
or several layers, all large, empty, many of them perforated, but 
seldom showing spiral incrassations ; their branches are also fas- 
cicled, which we vainly search for in other Mosses. In the true 
Leaf-mosses (Musci) we find no spiral incrassations in the cells, 
except in the teeth of Hymenodon pilifer and Fissidens ventrico- 
sus, and in the base of the leaves and female bracts of Heliconema 
Sprucei *. The leaves are only of three different kinds, viz. true 
vegetative leaves and bracts in all—but only in a few species folia 
mediana, now on the dorsal, now on the ventral side of the stem, 
in none so distinet as in Helicophyllum torquatum t, where they 
totally differ from the true leaves both in form and structure, but 
are very like the female bracts. The leaves are fixed transversely 
on the stem; only in Schistostega and Mittenia | we find them ver- 
tical on the sterile innovations ; they are always alternate, never 
opposite or connate, and entire, except in some Fabronie aud 
Splachnacee, especially in Tayloria laciniata, in which there is A 
distinct approach to laciniation: in no form is there present a 
* The thin, pellucid, and, in the lower end, perforated cells in the leaves and 
female bracts of Heliconema Sprucei show uncommonly broad, very thin, and, 
at their edges, most indistinctly effigurate annular incrassations, which fill up 
nearly the whole cell, and are of a very light green-brown colour. The cells, 
when old, very often fall into annular pieces. 
+ This solitary plant is placed by Dr. C. Miiller among the pleurocarpous 
mosses—a most unnatural arrangement. It is, no doubt, a link of Grimmiales 
nearest to Schlotheimia, and not at all a pleurocarpous form, but rather clado- 
carpous, as many of the acrocarpous are. 
I Mittenia, Lindb. in Ofv. V.-Akad. Förh, xix. p. 606, n. 5 (1862) is the 
same as Mniopsis, Mitt. in Hook. f. Fl. Tasm. ii. p. 187, t. 173. n. 7 (1858) ; 
but M. Dumortier has already, in his Comment. Bot. p. 114 (1823), called the 
Jungermannia Hookeri of Lyell, in Engl. Bot. xxxvi. t. 2555 (1813) Mniopsis 
Hookeri (Haplomitrium, N. Es. 1833). 
