296 DR. M. T. MASTERS ОМ SOME POINTS ІМ 
may almost all be alleged in support of this view. Nevertheless, when the evidence 
thus presented us is analyzed a little carefully, and correlated with the facts revealed to 
us by anatomy and development, it will be found that in most cases the facts related are 
not incompatible with the notion that the placenta is essentially an outgrowth from the 
carpellary leaf, and, by consequence, that the ovules, or their outer coats, are also deri- 
vatives from that source. Although the question, whether the ovular coat be a direct 
formation from the axis, or whether it originates from the carpellary leaf, may still be 
said to be undecided, yet the foliar character of the ovular coat will hardly now be 
contested. To the establishment of this point the investigations of monstrous Prim- 
roses by Brongniart and others* have mainly tended. It is not necessary to do more 
than recall these observations, because their accuracy has never been called in question. 
The illustrations now brought forward show clearly that the ovules of these particular 
Primroses are processes from the carpellary leaf, either marginal or detached by chorisis 
from its centre. This is in accordance with the views of Van Tieghem as cited in the 
extract previously quoted. Тһе occurrence of secondary carpels on the placenta, mixed 
with the ovules, also confirms this view. Іп this latter case we have a branched or 
compound carpel, some of the lobes of which are developed as ovules, others as secondary 
carpels. 
"These remarks, of course, apply to the outer coat of the ovule, and not to the nucleus. 
None of the monstrous flowers of Primulacez that I have hitherto examined have given 
any clue to the nature of the nucleus. 
Summary.—Taking now a general review of Primulaceous structure, normal and 
abnormal, the facts cited seem to lead to the following conclusions :— 
1. That the petals of most Primulaces (not in Samolus or Androsace) are late out- 
growths from the receptaeular tube outside the stamens, and posterior in development 
to them, but upraised with them by the upward growth of the so-called tube of the 
corolla. 
2. 'That the placenta of existing Primroses is a direct prolongation of the receptacle or 
axis, without any connexion with the sides or apex of the carpels. 
3. That the placenta in some (monstrous) flowers is an outgrowth, either from the 
margin or from the centre of the carpel, such outgrowth occasionally becoming wholly 
detached, the detached placentas, moreover, sometimes cohering one with another, and 
thus producing the appearance of a solid column directly prolonged from the receptacle. 
Such forms of placenta lead to the inference that the ancestral progenitors of Primulacec 
had parietal placentation, the monstrous forms being, on this view, looked on as 
reversions. 
_ 4 That both staminal and carpellary leaves may occasionally be divided or lobed, so 
that just аз we meet with compound or divided stamens in Malvacez and other orders, 
so the carpels of some orders are the homologues of divided leaves, as first pointed out 
ы Prof. Dickson. 
5. That the ovular coat of Primulaces is essentially foliar, representing either the 
* Бе spocially Brongniart, Ann. бе. с dnb 308, and Ann. Sc. Nat. 3° sér. t. xi. p. 20 (1844); 
Cramer, Bildungsah еони 
