Allgemeines. — Alorphologie, Befruchtung, etc. 
579 
Farbenlehre gewirkt, hier hat er die „Wissenschaft” wirklich ge¬ 
fördert. Matouschek (Wien). 
Farmer, T. B. and L. Digby. Studies in Apospory and 
Apogamy in Ferns. (Annals of Botany XXL p. 161 —199. 
pl. 16—20. 1907.) 
The cytological features of these processes were investigated in 
Lastvea pseudo-mas vars. polydactyla Wills, polydactyla Dadds and 
cvistata apospova Druery, Althyrium Filix-foemina vars. clcirissima 
Jones, clarissima Bolton and unco-glomevcitum Stansfield, Scolopen- 
dvium vulgare var. crispum Dvummondae. 
In Athyrium Filix-foemina var. clarissima Jones we have 
aposporous prothallia arising in connexion with the sporangia, 
as shown earlier by the investigations of Druery and Bo wer, 
and these prothallia again produce new sporophytes apogamously. 
The prothallia are of two types, expanded and bulbous, the former 
bearing very few sporophytes. The sporangia become abortive and 
aray peripheral cell of the sporangium or stalk may grow out into 
a prothallial filament. No meiosis (reduction) occurs in connexion 
with the formation of the gametophyte, the number of chromosomes, 
about 90, remaining constant and the divisions being of the 
premeiotic (somatic) type. Normal antheridia with motile antherozoids 
are produced as well as normal archegonia. The latter however 
though they are able to exert a chemotactie influence on the 
antherozoids, are never fertilized. The embryo arises as a bud on 
the gametophyte but there is no migration of nuclei from one 
prothallial cell to another and no change in the number of 
chromosomes, which is thus constant throughout the 1 ife¬ 
hist o ry of the plant. The cells and nuclei of the gametophyte and 
the antherozoids are of larger size than those of the type species 
and the nucleoli are different in the two cases. 
In Athyrium Filix-foemina var. clarissima Bolton we have again 
both apospory and apogamy, and the number of chromosomes is 
unaltered throughout the life-history. Prothallia may arise from the 
sorus or the apices of the pennae of the leaf. The gametophyte 
bears sexual organs freely and the antherozoids are attracted strongly 
even reaching the venter of the archegonium. No fertilization occurs 
but the oosphere develops directly into the new sporophyte. The 
cells of the sporophyte and prothallium are larger than those of the 
type species and smaller than those of the var. clarissima Jones. 
Athyrium Filix-foemina var. unco-glomeratum , Stansfield also 
exhibits both apospory and apogamy but it was not investigated in 
such detail as the others. The gametophyte arises from the sporangium 
and the embryo is endogenous in connexion with an archegonium, 
but its origin was not exactly followed; the number of chromosomes 
is constant throughout the life-history. 
In Scolopendrium vidgare var. crispum Drummondae we have 
the development of prothallia from the margin of the leaf and the 
sporophyte arises apogamously from the unfertilized oospheres 
which may become clothed with a w^all before the opening of the 
neck of the archegonium. There is in the life-history 7 no reduction 
or doubling of the number of chromosomes but the number exhibits 
some Variation being from 80 to 100; the ordinary 7 Scolopendrium 
vidgare has 62 and 31 chromosomes respectively in the two generations. 
In Lastrea pseudo-mas var. polydactyla Wills, as has long been 
