Notes. 
445 
is true that a few plants have been raised from the hybrid Polystichum 
aculeatum ( cruciatum ), yet I have sown spores from half-a-dozen ferns 
each year for six years without raising a single plant, and if this 
hybrid had been even moderately prolific there should now be 
thousands of plants in existence. Other hybrids, such as Lastrea 
remotci, Asplenium germanicum , and Asplenium marinum , v. microdon 
are to all intents and purposes sterile. This difference in fertility 
markedly distinguishes a variety from a hybrid species ; the progeny 
of a hybrid species is almost nil. 
E. T. LOWE. 
Shirenewton Hall, Chepstow. 
THE DISTRIBUTION OF LATICIFEROUS TISSUE IN 
THE LEAF. — In the autumn of 1886, Mr. L. A. Boodle and Miss 
A. Calvert, who were then working with me as research students, 
undertook, by my advice, an investigation of the course of the lati- 
ciferous tubes in the leaves of plants belonging to various natural 
orders. Our object was especially to test the accuracy of Haberlandt’s 
view that the laticiferous tubes serve as conductors of assimilated food- 
material, a view on which doubt had already been cast by the observa- 
tions of Schimper. Mr. Percy Groom’s paper ‘On the Functions of 
Laticiferous Tubes,’ in No. x. of the Annals of Botany, has suggested 
to me that a short summary of the results obtained, though not leading 
to any very positive conclusions, may be worth publication. The 
observations were made on sections, both transverse and superficial. 
The following account is taken, with only verbal alterations, from 
notes which I made at the time. 
Euphorbiaceae, 
Euphorbia cotinifolia. Laticiferous cells run in immediate contact 
with the spongy parenchyma, occasionally sending out branches be- 
tween its cells. 
Other cells or their branches very constantly occur in close contact 
with the palisade parenchyma. Some branches of the cells run im- 
mediately below the epidermis of both surfaces of the leaf, and in some 
