t)88 SUMMAUY OF CURRENT RESEARCHES RELATING TO 



Anatomy of the Salsoleae.* — M. P. A. Dangoard states that the 

 Salsolcju present several interesting structural peculiarities. In Noosa 

 spinosisiiima Moq. three fibrovascular bundles detach thcnisolves from 

 those which form the central cylinder of the axillary branch ; tho 

 median bundle is destined for tho leaf, tho two lateral ones bifurcate 

 wlicn near the cortex, one ramification appi'oaches the median bundle, 

 while the other furnishes tlie bundles which are met with in tho cortex 

 of the stem. The cortical parenchyma includes (1) the epidermis; 

 (2) a single layer of palisade tissue, intcrrujitcd in several places ; (3) a 

 layer of cubical cells ; (4) a large number of small bundles with the 

 xylcm on tho outside; (5) a C(dourless parenchyma. In certain of tho 

 Salsolejc, for example Anabasis aphylla L., the structure of the cortical 

 parenchyma is slightly different. 



Thyllfe.f — Dr. H. Mtdisch has investigated the phenomena connected 

 with tho formation of tliylloe in various tissues. They may occur in 

 spiral, annular, or pitted vessels. In tho first two cases tho extremely 

 thin wall of the vessel coalesces completely with the wall of tho 

 adjoining parenchymatous cell to form a homogeneous membrane which 

 grows out into a thylla. In pitted vessels it is the closing membrane 

 of the pit which grows out into the thylla. The remarkable growth of 

 the membrane in all these cases appears to confirm the view of Wiesner 

 that the growing cell-wall is permeated by protoplasm, and owes to it 

 its power of growth. Tho thylla does not, as a rule, become shut oflf 

 from the parenchymatous cell by a septum ; they arc therefore not them- 

 selves correctly described as cells. In a few cases they become 

 sclcrotized. 



The number of genera in which thyllte have at present been observed 

 amounts to about 100. The greater number occur in the natural orders 

 Marantacere, Musacege, Juglandcfe, Urticacefe, Moreae, Artocarpea), 

 Uimaccje, Anacardiacenc, Vitaccte, Cucurbitacea), and Aristolochiaceso. 



The most important function of thyllae aiii)ears to be to serve as 

 stoppers, and secondly as organs for the storing up of starch. The 

 stomita become in some cases stopped by protrusions from the meso- 

 phyll-cells which project into the pore. 



(4) Structure of Organs. 



Rooting of the Albumen of Cycas.J — M. P. Duchartre states that of 

 the two i^arts which constitute the kernel of an adult albuminous seed, the 

 one, the embryo, is essentially living and active, and susceptible of vege- 

 tating, while the other portion, the albumen, has been regarded until tho 

 present time as inactive and inert, and not susceptible of ulterior 

 development. The author, however, has found that the seeds of Cycas 

 Thouarsil R. Br., a great number of which often contain no embryo, can 

 not only rupture the three zones of seminal iutegumeut, but can even 

 form adventitious roots. 



Subterranean Shoots of Oxalis.§— Mr. W. Trelease describes the 

 underground shoots of Oxalis violacea. The watery tap-root is very 

 strongly developed. From the withered bulb just above this protruded 



* Bull. Soc. Bot. France, xxxv. (1888) pp. 197-8. 



t SB. K. Akad. Wiss. Wien, June 14, 1888. See Bot. Centralbl., xxxv. (1888) 

 P- 222. X Bull. Soc. Bot. France, xxxv. (1888) pp. 243-51. 



§ Bot. Gazette, xiii. (1888) p. 191 (1 pi.). 



