PROF. F. О. BOWER ON APOSPORY AND ALLIED PHENOMENA. 317 
axis; as examples of this may be cited the prolifications of the fertilé cones of Equiseta* ; 
of Selaginella Lyalliit,in which many of the sporangiferous cones were found by Goebel 
to be proliferous, the apex of the axis having grown further, and branching, while the 
sporangia of the upper part of the cone were arrested; of the cones in various Gymno- 
sperms | so frequently made use of by various writers as throwing light on the morpho- 
logy of the cone; lastly, in the Angiosperms simple prolification, associated often with 
increase in size of the individual floral leaves beyond the normal, as well as increased 
length of the axis, has been from early times an object of common observation $. Such 
proliferations are, in a large number of recorded cases, associated with a partial or com- 
. plete arrest of spore-formation, and whichever phenomenon be regarded as the true 
cause of the abnormal development, there can be little doubt that they are closely related 
to one another, in fact, that there is, in these monstrosities, evidence of a correlation of 
sporal and vegetative development. A comparison of these cases with certain Pterido- 
phyta will naturally suggest itself, and it is hardly necessary to point out that the 
relations of the vegetative to the sporal development on the fronds of Osmunda regalis, 
Aneimia phyllitidis, Blechnum Spicant, various species of Acrostichum, &с., clearly show a 
similar correlation, extending, however, in these cases only to parts of the individual 
leaf. 
Passing now to the second head, under which are included all cases of the formation 
of new buds of а sporophorie character following on partial or complete sporal arrest, it 
is obvious that we shall be dealing with phenomena which will graduate off by imper- 
ceptible degrees to cases of ordinary sporophorie budding ; or, to put it in other words, 
adventitious buds of a sporophoric character are produced commonly upon the sporo- 
phore; sometimes they may be associated with sporal arrest, at other times they appear 
to be independent of it. Putting aside the latter, there remain a number of cases where 
budding is associated with sporal arrest. Thus, of the Ferns above described, adventitious 
sporophoric buds are formed from the base of the sorus in Athyrium F.-f. var. plu- 
mosum, subvars. elegans and divaricatum, while the formation of spores is, in these cases 
at least, partially arrested; again, іп Aspidiwm erythrosorum, var. prolificum, there is 
a development of a sporophoric bud from the bases of certain sori; but the number of 
these is smaller than in the cases above mentioned, and it is further to be noted that the 
arrest of the sporangia and spores is less complete. It will be sufficient in connection 
with these examples to cite the well-known formation of bulbils or sporophorie buds on 
the fronds of the Asplenia, of Ceratopteris, &c., in which the formation of the buds 
cannot be directly correlated with arrest of spore-formation. In Isoëtes a pregnant 
+ Milde notes it in Е. litorale, in which the spores are arrested, though it is not a constant character of this plant 
and in other species. Comp. also Ridley (Journ. Linn. Soc., Bot. xx. p. 47), who describes it in Е. maximum, but 
says nothing of the condition of the spores ; also Goebel (Ber. d. bot. Gesellsch. 1886, p. 184), who traced the corre- 
lation experimentally. 
T Goebel, Bot. Zeit. 1880, p. 821. 
+ Masters, Veg. Terat. p. 103, also p. 115, where the early literature is quoted. Comp. also more recent writings 
by Eichler, Strasburger, &c. | 
$ Masters, Veg. Terat. p. 136, &c. ; also, as an extreme case, Henslow, Journ. Linn. Soc., Bot. xix. pl. xxxii. 
SECOND SERIES.—BOTANY, VOL. II. 9 B 
