BOOKS AND CURRENT LITERATURE 



The Eusporangiate Ferns. 1 It is just twenty years since Professor 

 Campbell first called attention to the Ophioglossaceae and Marattiaceae, 

 which together make up the Stipulatae of Sachs, or Eusporangiatae 

 of Goebel, as the most primitive of living Filicales. The present paper 1 

 gives us the consummation of the investigations initiated by the author 

 two decades ago. It furnishes a worthy example of long-sustained 

 interest and persistent effort in the solution of one problem. The 

 outcome is the accumulation of a large series of facts concerning the 

 structure and development of these ferns, which serve as a substan- 

 tial foundation for his hypothesis concerning their relationship to each 

 other and to other Filicales. Besides summarizing the earlier work of 

 the author and that of other writers, the book gives the results of the 

 detailed -study of fourteen species of these two families, including exam- 

 ples of all the genera except the recently discovered Arcangiopteris 

 and M acroglossum . Some of the subject matter and certain of the 

 drawings have already appeared in the recent papers of the author. 



The memoir is divided into three parts, dealing respectively with the 

 Ophioglossaceae, the Marattiaceae and the origin and relationship of 

 the Eusporangiatae. In Part I Campbell discusses, in one section, the 

 germination of two species of Ophioglossum; the structure, including 

 histology and the mycorrhiza of the prothallus of four species of Ophio- 

 glossum, one of Botrychium and one of Helminthostachys; finally, the 

 development of the sexual organs is described, including the spermato- 

 genesis of all three genera. In a second section or chapter, on the em- 

 bryo, the origin of the primary organs of the sporophyte is described for 

 two species of Ophioglossum, and one of Botrychium . The most striking 

 feature of this development is the late appearance of the stem, in an em- 

 bryo that for a long time consists solely of a root and a cotyledon with 

 a continuous vascular bundle running through both. The most impor- 

 tant discovery described in a third section, on the young sporophyte, 

 is the character of the vascular system of the latter. This is made up 



Campbell, Douglas Houghton: The Eusporangiatae; The Comparative Mor- 

 phology of the Ophioglossaceae and Marattiaceae. Cam. Inst. Wash., Publ. 

 141, pp. 235. pis. 13. figs. 192. 1011. 



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