192 Farmer and Dig by. — Studies in Apospory and 
B. Meiosis absent, apogamy obligate. 
1. Par then apogamy, sporophyte originates from oosphere- — 
(a) After formation of spores : 
Examples: Thalictrum pur pur ascens (Juel), Eualchemilla sp. 
(Murbeck, Strasburger), Hieracium excellens (type 2 of 
Rosenberg), Antennaria alpina (Juel). 
((3) With apospory: 
Examples : Athyrium Filix-foemina var. clarissima , Bolton, 
S colop endrium vulgar e var. crispum Drummondae , Hieracium 
excellens (type 3 of Rosenberg). 
2. E'uapogamy , sporophyte originates from gametophytic tissues — 
(a) After formation of spores: 
Example: possibly Lastrea pseudo-mas var. crist ata apospor a at 
its first origin. 
(/ 3 ) With apospory : 
Example: Athyrium Filix-foemina var. clarissima , Jones; 
Lastrea pseudo-mas var. cristata apospor a. 
Of course any classification is likely to contain anomalies, and it may 
be objected that it is unnatural to make the presence or absence of spores 
a means of subdivision. It is true that it is not perhaps very logical, but 
it is a convenient character, especially in connexion with the Phanerogams, 
although there is in them one irregular feature that demands a passing 
comment. The limits between the spore and the spore-mother-cell are 
apt to disappear, and thus it might be argued that, strictly speaking, many 
forms are really aposporous which are not usually reckoned as such. For 
example, when the spore-mother-cell at once becomes the cell in which the 
gametophyte is produced, as in Lilium , one might — though not very 
usefully — maintain that the spore stage properly so called had been cut out 
of the life-history. 
On the whole we have preferred to regard all the single cells in 
which the phanerogamic gametophyte is produced as spores, whether they 
go through the tetrad division or not, if there seems to be sufficient reason 
to refer them to an archesporial origin. In Rosenberg’s type 3 of Hieracium 
excellens and H. flagellare the single cell in which the gametophyte is 
produced is clearly not referable to such a source, and it is therefore classed 
with the aposporous forms. This distinction is the more necessary 
because of course the gametophyte of the Phanerogams is always intra- 
cellular, but it is theoretically quite possible for the enclosing cell to 
belong even to extra-sporangial tissue, although no instance of the kind, 
so far as we are aware, has been as yet discovered. 
Amongst the Ferns, we are not at present acquainted with an example 
in which spores are produced in the absence of meiosis, but their relatively 
common occurrence in the ovules of Phanerogams renders it not im- 
