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XIX. On some Points т the Morphology of the Primulacee. Ву M. T. MasrEns, M.D., 
Ғ.Е,ғ., F.L.S., $c. 
(Plates XXXIX.-XLI.) 
Read June 7th, 1877. 
THE most generally interesting points connected with the structure of the flowers of the 
Primulace: reside in the superposition of the stamens to the petals, the free central pla- 
centa, and the nature of the ovules. 
Much discussion has taken place with reference to all these points. The explanation 
of the observed facts, and the arguments and inferences based upon them, have been de- 
rived from a study— 
1. Of the comparative morphology of the genera of the order and of its allies. 
2. Of the mode of development or organogenesis of the parts of the flower. 
3. Of the minute anatomy of the flowers, and especially of the distribution of the 
vascular bundles within them. 
4. Of the teratological phenomena observed in the order. 
These latter are exceedingly numerous, and have consequently attracted the attention 
of a proportionate number of observers. It is to them that I propose to devote much 
attention in this paper, though I would deprecate the notion that teratological changes 
per зе are to be taken as safe guides to the explanation of structure. The evidence they 
afford always requires to be controlled by that derived from other sources. 
I must preface my remarks by stating that I have personally examined during the last 
. twenty years a very large number of such instances, while my note-book teems with 
references to what has been published by others in this country and abroad. 
It would be hardly possible to cite all these references, and certainly not desirable to 
do so; for many of them are, relatively speaking, of little importance to the matters I 
propose now to bring under the consideration of the Society. Such, for instance, are the 
malformations affecting the stem, leaves, or inflorescence, phenomena interesting in 
themselves, but which throw no special light on the structure of the order. 
In passing, I may make allusion to the very great frequency with which deviations 
from the usual or, as it is called, typical structure occur in this group. Ав is well known 
to all who pay attention to these matters, malformations are much more common in some 
orders than in others. In the case of Primulacez a glance at the recorded literature 
will suffice to show how unstable, if I may so say, is the structure of certain genera of 
this order. Were it possible to enumerate individual cases, the fact would be even more 
prominently noticeable. 
From the frequency with which thas changes occur in such genera as Primula and 
Cyclamen it might be inferred that the changes induced by cultivation afforded sufficient 
reason for these structural aberrations. No doubt this is to a certain extent true. But 
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