ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 249 



Eichhornia azurea and crassipes. The best mode of treatment he finds 

 to be to soak the sections in potash for twenty-four hours, treating with 

 acetic acid, and then mounting in glycerin, or to stain with Kleinen- 

 berg's haematoxylin after treatment with potash, and mounting in Canada 

 balsam. Examined in this way he finds that, even in the youngest 

 stages of the adventitious roots, it is quite impossible to refer the root- 

 cap to the same initials which give rise to the dermatogen and periblem ; 

 there is a distinct calyptrogen layer. The young adventitious roots of 

 the Pontederiaceaa have, in fact, very much the same structure as the 

 primary roots of Pontederia cordata, and belong therefore to the type of 

 the Gramineas. 



(4) Structure of Organs. 



Endosperm of Gelsomineae ( Jasminese).* — Prof. E. Pirotta has tested 

 the correctness of the usual statement that in this family, a suborder of 

 Oleaceas, comprising the genera Jasminum, Menodora, and Nyetanthes, 

 the endosperm is entirely wanting or reduced to a mere rudiment. He 

 finds, on the contrary, endosperm invariably present in the mature seed. 

 In Menodora, and in some species of Jasminum, the cotyledons are 

 foliaceous, and the endosperm is then well developed ; in other species 

 of Jasminum the cotyledons contain a large amount of reserve-substance, 

 and in these the endosperm, though still always present, is reduced to a 

 small number of cells. 



Salt-excreting glands of Tamariscineae.f — Dr. E. Marloth contests 

 Volkens' theory that the glands on species of Tamariscineas inhabiting 

 the deserts, such as Meaumuria hirtella, which excrete an incrustation of 

 salt over the surface of the organ, have the power, through their hygro- 

 scopic properties, of taking up the water which is precipitated through 

 the air, and transmitting it to the assimilating tissue. He maintains 

 that the purpose of the incrustation is, on the one hand, to serve as a 

 non-conductor of heat, on the other hand to diminish transpiration. 



To this Herr G. Volkens replies, J pointing out that at all events the 

 second hypothesis of Dr. Marloth is hardly consistent with the fact that 

 the excretion of salt is in the form of a loose and very unequally 

 distributed powdery mass. 



Organs for the absorption of vegetable food-material by plants 

 containing chlorophyll. § — Herr L. Koch describes peculiar organs on 

 the roots of species of Melampyrum, especially M.pratense, connected with 

 the absorption of nutriment from the soil in which they grow, and 

 which contains great quantities of the decaying roots of grasses and 

 stem of mosses, and the mycelium of Fungi. The root-system of 

 Melampyrum, penetrating into this substance, consists of a primary root 

 and lateral roots, which force their way through this layer into soil 

 containing very little or no organic matter. These roots grow to a 

 considerable thickness, and serve as a support to long slender roots 

 proceeding from these, which play the greatest part in the absorption 

 of food-material. These slender roots are of endogenous origin with 

 rudimentary root-cap, and proceed often in crowded clusters from spots 

 in the principal roots, which are in contact with the organic substratum. 



* Malpighia, i. (1887) pp. 427-34 (1 pi.). 



t Ber. Deutsch. liot. Gesell., v. (1887) pp. 319-24. Cf. this Journal, ante, p. 81. 



X Ibid., pp. 434-6. r 



§ Ber. Deutsch. Bot. Gesell., v. (1887) pp. 350-64. Cf. this Journal, ante, p. 81. 



