580 Morphologie, Befruchtung, Teratologie, Cytologie. 
known, the prothallia arise normally from the spores but they bear 
no archegonia the embrvo arising apogamousty. The earlier results 
(vide Bot. Centralbl. XCIII. p. 54. 1903) in which they observed a 
migration of nuclei from cell to cell and the fusion of these nuclei 
in pairs was confirmed. By this fusion is brought about the doubling 
of the chromosomes of the cells which are to give origin to the 
sporophytes. In L. pseudo-mas var. polydactyla Dadds we have a ver} r 
similar condition of affairs, the prothallia being produced normally 
and nuclear migrations and fusions being found just behind the 
growing point of the gametophyte, the region from which the young 
plantlets spring. 
In Lastvea pseudo-mas var. cristata apospora Druery we have 
an apogamous form in which the number of chromosomes is neither 
doubled nor reduced during the life-history but the number 
appears to be the gametophytic number. The plant arose as a 
sporeling from a stray Spore in a fernery and so would have the 
reduced number of chromosomes, and the embryos are produced by 
budding without any process of nuclear migration. The number of 
chromosomes varies slightly being 60 in the gametophyte and in 
the embryo either 60 or about 78. 
In the ‘general discussion’ the authors point out that the 
varieties of Lastrea and Aspidium investigated show, when compared 
with the type, not only variations in form, but cytological differences 
in the form and nature of the nucleoli, the size of the cells and 
nuclei, the size of the antherozoids, and the number of chromosomes. 
Very interesting tables are given for the two genera showing the 
differences in these respects between the type and the various 
varieties. It is interesting to note that while in the varieties of 
A. Filix-foemina studied the chromosome number is greater than 
the type, whereas in L. pseudo-mas var. polydactyla the number is 
less than that of the type. The question of the inconstancy of the 
number of chromosomes which has been proved to exist in certain 
cases is discussed and its possible relation to the production of 
“Sports or unlooked for variations” is pointed out. 
The following Classification of the cases of apogamy and apospory 
is suggested. 
A. After Meiosis. 
1. Normal fertilization. 
2. Pseudapogamy (apogamy with fusion of gametopltytic nuclei) 
Lastrea pseudo-mas var. polydactyla; Uredineae. 
3. Euapogamy (apogamy without any nuclear fusion) L. pseudo- 
mas var. cristata apospora at its first origin. 
4. Parthenogenesis. No case definitety known at present. 
B. Meiosis absent (apogamy thus obligate). 
1. Parthenapogamy (sporophyte from oosphere). 
a) After formation of spores. Thalictrum purpurascens (Overton) 
Eualchemilla sp. (Murbeck, Strasburger) Hieracium excellens (type 2 
of Rosenberg) Antennaria alpina Tuel. 
b) With apospory. A. Filix-foemina var. clarissima Bolton, 
Scolopendrium vulgare var. crispum Drummondae, Hieracium 
excellens (type 3 of Rosenberg.) 
2 Euapogamy (sporophyte from gametophytic tissues.) 
a) After formation of spores. Possibly L . pseudo-mas var. cristata 
apospora at its first origin. 
b) With apospory. A. Filix-foemina var. clarissima , Jones, 
L. pseudo-mas var. cristata apospora. 
