276 NATURAL SCIENCE [October 



ment of the vascular bundle from its most rudimentary form to that 

 of the fully developed stem is fully known. These are illustrated in* 

 the work before us. The structure of the stems of Sphenophyllum 

 insigne and Sphenophyllum plurifoliatum are given in detail. 



The cones of Sphenophyllum offer an interesting field of study. 

 Though the vegetative system of all the species possess many points 

 in common, the sporangia in their number and details of attachment 

 to the bract, differ considerably in the few species of which we possess 

 any concise knowledge. As illustrating these differences in the 

 structure of Sphenophyllum cones, several species are described in 

 detail under the generic name of Sphenophyllostachys. The first, 

 Sphenophyllostachys Dawsoni, Will, sp., is almost certainly the cone of 

 Sphenophyllum cuneifolium, Sternb. sp. In this cone each bract bears 

 three sporangia and each sporangium is supported on a slender sporan- 

 giophore, but as all the sporangiophores arise from the same point on 

 the bract and are placed in sequence, the sporangium most distant from 

 the axis of the cone has a much longer sporangiophore than that next 

 the axis. In Sphenophyllostachys Boemeri, Solms Laubach sp., the in- 

 curved end of each sporangiophore bears two sporangia. There is 

 here also, probably, three concentric circles of sporangia. In Spheno- 

 phyllum trichomatosum, Stur, each bract seems to have borne a single 

 sessile sporangium. It is therefore seen that although in the vegetative 

 system, all the Splienophyllum possess many common characters, in the 

 arrangement of the sporangia, the cones show important differences. 

 Mr Seward rejects, and we believe correctly, the idea that Spheno- 

 phyllum was an aquatic plant. There is absolutely no evidence in 

 support of this view and very much against it. 



Mr Seward's " Fossil Plants " is a most successful treatment of a 

 difficult subject. All of importance is brought forward and impar- 

 tially discussed and numerous references are given to the original 

 papers consulted. The work however is not a compilation, but em- 

 bodies the opinions of one who has done much good original work in 

 Palaeophytology. Such a book has long been a desideratum, and its 

 appearance must give a great stimulus to the study of fossil botany in 

 Britain. Mr Seward's style is clear and concise, and the many pitfalls 

 into which beginners are apt to stumble are clearly pointed out. We 

 heartily congratulate the author and publishers on the completion 

 of the first volume of " Fossil Plants," and have only to express the 

 hope that ere long the completing volume will be issued. 



A full list of the works referred to in the text is appended and the 

 index, a most important matter, is very full. The illustrations are 

 also good and well chosen. K. 



Bau und Lkben unseber Waldbaume. By Dr M. Biisgen. 8vo, pp. viii + 230, with 

 100 tigs, in the text. Fischer, Jena, 1897. Price, 6 marks. 



Dr Busgen has produced a useful introduction to the study of 

 forestry, which will, doubtless, find a welcome in the various forestry 

 schools on the Continent. Naturally, much of the subject-matter is 

 similar to that of the general text-book of botany, embracing the 

 principles of the anatomy and physiology of plants. But the woody 

 plant is always kept in view, and made to supply the necessary illus- 



