ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 611 



structures (by Frank as the originators of the bacteria themselves), the 

 author is inclined altogether to doubt their fungal character, and to regard 

 them as of the same nature as the bacteroid tissue itself. 



The explanation given by Tschirch of the universal occurrence of these 

 structures in the Leguminoste, is the unusually large jiroportion of nitrogen 

 required by this class of plants ; they are therefore especially well 

 developed when leguminous plants are grown in a soil containing but a 

 small quantity of humus or nitrogenous constituents. They attain their 

 maximum of development when the plant is in flower, gradually giving up 

 their nitrogenous contents as the seeds ripen. They are not organs of 

 absorption, and, as a general rule, the conversion of nitrates into albumi- 

 noids has taken place before the food-material reaches the tubercles. 



Swellings on the Roots of the Alder and Elaeagnaceae.* — A fresh ex- 

 amination of these structures has led Herr B. Frank somewhat to modify 

 his own previous view as to their nature, and to differ entirely from those 

 who regard them as due to parasitic fungi. He finds the ai^pearance of a 

 carefully prepared section to differ in no respect from that of an ordinary 

 spongy parenchyma full of protoplasm ; and the so-called vesicles, to which 

 such different interpretations have been given, to be nothing but accumula- 

 tions of newly -formed albuminous substances in the rounded spaces of the 

 originally porous protoplasmic structure. 



These swellings are therefore identical in structure and function with 

 the tubercles on the roots of the Leguminnsfe as explained by Tschirch. 

 They are organs for the temporary storing-up of albuminoids, to be again 

 dispersed to those parts of the plant where they are required for the 

 formation of new organs. The alleged parasitic fungi Schinzia Aim and 

 Leguminosarum, Plasmodiophora Alni, and Frcmhia subtilis, must therefore 

 be erased from mycology. 



Shoots of Pyrola secunda.f — Prof. Kjellman describes the structure 

 by means of which the so-called " wandering " of Pyrola senmda takes 

 place. It depends on an annual increase and extension of the crown of 

 the root, which promotes the exposure of the flowers and the consequent 

 dispersion of the seeds. 



Relationship between Stipule and Leaf. J — Dr. M. Kronfeld gives 

 further details of his experiments on the effect on a stipulate leaf of 

 removing the stipules. It is only where these are large that the removal 

 of either lamina or stipules appears to have a direct effect on the develop- 

 ment of the other. In Latliyrus Aphaca and affinis the very large stipules 

 appear to be the direct result of a reduction of the lamina to the condition 

 of a tendril. 



Comparative Anatomy of Tendrils.§ —Herr G. Worgitzky describes 

 the mechanical structure of tendrils in a large number of j)lants belonging 

 to a variety of natural orders, and summarizes the results as follows : — 



The arrangement of the tissues in tendrils or other organs performing 

 the purpose of tendrils, is intimately connected with the requirements of 

 their functions. The mechanical adaptation varies before and after the 

 clinging to a support ; this clinging is associated with more or less com- 

 plete anatomical changes. The mechanical adaptation is also different in 



* Ber. Deutsch. Bot. Gesell., v. (1887) pp. 50-8 (1 pi.)- Cf. this Journal, 188G, p. 1033. 



t SB. Naturv. Studentsallsk. Upsala, Oct. 26, 1886. See Bot, Ccntralbl., xxx. 

 (1887) p. 94. 



X Verhaudl. Zool.-bot. Gesell. Wien, xxxvii. (1887) pp. 69-80. Cf. this Journal, 

 ante, p. 271. 



§ Flora, Isx. (1887) pp. 2-11, 17-25, 33-46, 49-56, 65-74, 86-96 (1 pi.). 



