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brief biographical notice, with a short list of similar publications, 

 most of which appeared last year, but does not include one by Mr. 

 J. 0. Willis in Xntund Science for April, 1893. In view of the 

 importance and interest attaching to Sprengel's work, would it 

 not be worth the while of some English publisher to bring out a 

 translation ? A. B. Bendle. 



llcchrrches sur V Anatomic compare? du : /-'i,re Tlnmhenjia L. hi. Par 

 Chables Boulet. Extrait du Bulletin de l'Herbier Boissier. 

 Tome II. Avril et Mai. 1894. 

 Db. Chables Boulet, a pupil of Professor Chodat of Geneva, 

 has examined the structure of all the species of Thunbenna ut 

 which he was able to get material. Anomalies in the stem-structure 

 of various species of the genus have, indeed, in recent years been 

 described by Bussow, Vesque, Badlko r er, and several other authors, 

 but hitherto study in detail from species to species has not been 

 undertaken. Dr. Boulet finds the epiderm cells to be largely col- 

 lenchymatous, and only to a slight extent cuticulansed, and he 

 notices the presence of sclerenchyme fibres in the hypoderm, as 

 well as of lacuna; in the cortex, which latter are, in some species, 

 quite large, and give the cortex the appearance of that of an 

 aquatic plant. There is in all cases a well-differentiated endoderm, 

 and within it a usually 1 -layered pericycle, reinforced in places by 

 sclerotic elements. The climbing species present three types of 



Str ^ 1 ^The l Rexacentris type, characterised by the indefinite pro- 

 duction of alternating xylem bridges and phloem-islands in the 

 interfascicular radii. 



ii. Type of T. elata and reticulata 

 phloem-' 



iii. This type includes T. fray 

 small phloem-islands in the xylem, into wn 

 wedges of extraxylemic phloem, the cambium- 



, and a few others 



lloem-islands immersed in the axial part of 

 irect species have normal xylem. 

 nomalies are described. Especially note- 



ifter a time 



medullary xylem-islands, and a woody cylinder, which 

 is fragmented just as occurs with the genus Mendom ■■>. 

 is peculiar too, inasmuch as its phloem-islands are restrictea to two 

 interfascicular radii on opposite sides of the stem, and these islands 

 may be in contact with the pith. . 



The author carefully describes the various histological elements, 

 but it must suffice to notice the curious ones discovered by Bussow, 

 and called by Badlkofer " raphidines." The development of these 

 is gone into, and they are shown to arise as thickenings of the 

 parent cell's wall which, by dissolution of its mid-lamella, are set 



