ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 475 



Abnormal Sporocarp of Salvinia.* — A. J. Gray publishes a note 

 on an abnormal sporocarp of Salvinia nutans, containing both mega- 

 sporangia and microsporangia, an abnormality only once before observed. 

 Normally the Hydropteridege have the two sets of sporangia in separate 

 sporocarps. In Azolla, in the microsori the megasporangium aborts at 

 an early age ; in the megasori the microsporangia fail to develop. In 

 Salvinia, on the other hand, this abortion of mega- and micro-sporangia 

 respectively is not found save in very rare abnormal cases. 



Floats and Stripes in Marsilia.f — G-. Senn gives an account of 

 the float-bladders and intercostal stripes of a New Caledonian aquatic 

 form of Marsilia. The formation of the floats depends upon the 

 enlargement of certain radially arranged air-chambers, such as occur in 

 other parts of the leaf -stalk. The intercostal stripes on the underside 

 of the leaf are composed of small straight-walled epidermis cells, rich in 

 tannin and not developed beyond the embryonal stage, clearly owing to 

 malnutrition. The brown colour is due to tannin-derivatives. 



Adventive Buds in Ceratopteris.J — W. Bally writes about the 

 adventive buds and allied structures on the primary leaves of ferns. 

 He sums up his results as follows. 1. The earliest stages of the 

 adventive buds of Ceratopteris thalictroides showed two large cells. 

 2. From these cells arise a stem-apical cell and a leaf-apical cell. 3. The 

 rudiments of the second leaf originate in a segment of the stem-apical 

 cell. 4. On the later leaves adventive buds arise in similar fashion. 

 5. The adventive buds on the primary leaves of G. thalictroides do not 

 germinate in a normal manner. 6. To make them develop one must 

 cut off the leaves, or cut off the apical cell, or cut through the vascular 

 bundles of the leaf. 7. Buds cut off and cultivated on Sphagnum 

 develop leaves of simplified structure. 8. The prothalloid outgrowths 

 on the primary leaves of Polypodium aureum received from Goebel 

 show a tendency to branch, the lobes being of a leaf -like character, and 

 one of them produces the apical cell.- 9. The formation of the apical 

 cell was retarded by malnutrition. 10. In P. lycopodioides some struc- 

 tures intermediate between prothallia and leaf-like outgrowths were 

 successfully elicited on the primary leaves. 



Fossil Equisetaceae and their Structured — P. II. Fritel and 

 R. Yiguier give an enumeration of the fossil species of Equisetum, 

 calling special attention to those the tubers of which are known. 

 Having obtained good material, they describe and figure the structure 

 of the tubers of E. stellare and the stems of E. noviodunense. Their 

 studies show that the structure is the same as that of present day 

 species, and that the genus is no more likely to have altered in its 

 internal morphology than in its external. And once more is de- 

 monstrated how indispensable it is to study the anatomy of fossil 

 plants, since paleontologists of high repute have mistaken the tubers of 

 E. stellare for fruits of palms or of Rubiaceae. 



* Notes Roy. Bot. Gard. Edinburgh, xx. (1909) pp. 251-2 (pi.). 



f Ber. Deutsch. Bot. Gesell., xxvii. (1909) pp. 111-19 (pi. and fig.). 



X Flora, xcix. (1909) pp. 301- 10 (figs.). 



§ Rev. Gen. Bot., xxi. (1909) pp. 129-42. 



