NOTE 
PRELIMINARY NOTE ON OCCURRENCE OF STOMATA IN HYPO- 
GEAL COTYLEDONS. — It is generally assumed that cotyledons which on the 
germination of the seed remain within the testa and in the majority of cases, 
also below ground, have been derived at some time or another from cotyledons 
that emerge from the testa. Goebel (‘ Organography of Plants/ Part II, p. 403) 
states that ‘ in hypogeous cotyledons the functioning as assimilation organs has 
only been given up at a late period in connexion with the deposition within 
them of reserve material, and that in consequence of this they no longer reach 
the light \ 
The striking results obtained by A. W. Hill in his work on the ‘ Morphology and 
Seedling Structure of the Geophilous Species of Peperomia ’ (Ann. Bot., vol. xx, 1906) 
suggested an investigation into the occurrence of stomata on hypogeal cotyledons present 
in dicotyledonous and in monocotyledonous seeds. If stomata occur on hypogeal as 
they do on epigeal cotyledons this may be regarded as an instance of the retention of 
a primitive structural feature that has now become useless. 
It has been found very difficult to secure adequate supplies of material, and seeds 
have therefore been examined just as they could be obtained and not according 
to any scheme of classification. In the case of large cotyledons the upper and lower 
epidermis was removed by tangential section. In the case of minute cotyledons the 
whole leaf, and in some cases the whole seedling, was rendered transparent in caustic 
potash. If stomata were observed their relative numbers and distribution were noted. 
If, on the other hand, stoma initials only were found the seeds were germinated 
in the hope that the initials would develop fuither. Some few of the seeds were 
germinated in the normal way, the cotyledons remaining within the seed coat. From 
other similar seeds the testa was removed so that the cotyledons were freely exposed 
to light and air, the object being to induce the cotyledons of such seeds to revert to 
their original habit of developing to a greater or lesser extent, as assimilatory and 
transpiratory organs. In all cases the seeds were germinated on moist Sphagnum and 
not in soil. 
During the investigation several difficulties were encountered. In the first place, 
very little literature is available giving accurate data as to the names of plants 
possessing the hypogeal character in their cotyledons. Lubbock’s two volumes 
‘On Seedlings’, Kerner’s 1 Natural History of Plants’, Goebel’s ‘ Organography 
of Plants ’, and occasional odd papers on single seedlings have supplied a certain 
amount of information, but these are by no means exhaustive. To germinate all 
available seeds for the purpose of observing the nature of their cotyledons seemed an 
unnecessary undertaking if such germination has already been carried out for other 
purposes. Miss Blackburn, of Bedford College, London, has kindly communicated 
a list of seeds with hypogeal cotyledons compiled from her own observations, 
[Annals of Botany, Vol. XXVIII. No. CXI. July, 1914.] 
