112 BOTANICAL GAZETTE. [April, 



Development of Pilularia. 2 



In undertaking the study of this interesting plant Dr. Campbell had 

 in view two things, viz.: the investigation of its life-history, and the de- 

 termination how far the parrafin imbedding-process was of practical ap- 

 plication in the study of vegetable embryology. The method of imbed- 

 ding was found eminently successful, and, as a consequence, the life-his- 

 tory of Pilularia is worked out as it never has been before. The material 

 was kept in constant germination and the investigation was a most ex- 

 haustive one. The subject is treated under the following captions : the 

 microspores and male prothallium, the macrospore and female prothal- 

 lium, the embryo, the leaf, the root-quadrant, the stem-quadrant, the foot- 

 quadrant, the structure and division of the nuclei in the embryo, subse- 

 quent growth of the young plant, and the relationships of the Marsiliaceae. 

 The study of the microspores is especially interesting, as the author suc- 

 ceeded in removing the exosporium and following the development of 

 the prothallium and antheridium with great precision. The characters 

 of these structures are much more nearly those of the true ferns than has 

 heretofore been supposed. In reference to this relationship the author 

 says: "Botanists have long recognized the evident relationship of the 

 Marsiliacese to the true ferns, especially to the Polypodiace^, and this 

 view is strengthened by the very great resemblance in the structure of 

 the antheridium. Whether a more complete knowledge of Saiviniacese 

 will show further relationships between them and the Marsiliacese is 

 doubtful, for apart from both families being heterosporous, they have lit- 

 tle in common." 



Xtie Families of Plants. 



Engler and Prantl's magnificent work 3 has just reached the end of 

 the second volume, the first one completed. It makes a book of 1024 

 pages, and contains 803 illustrations, which are made up of 3537 separate 

 figures. These illustrations are not only abundant, but are of the finest 

 execution. The work must be of immense service to botanists, and the* 

 low price of the parts places it within the reach of all. The various parts 

 have been noticed in this journal, but with the conclusion of the volume 

 it is a fitting time to note the contents. The orders presented are as fol- 

 lows: Alismacese (Buchenau), Amaryllidacese (Pax), Aponogetonaceae 

 (Engler), Araeese (Engler), Bromeliaceae (Wittmack), Burmanniaceae 

 (Engler), Butomacese (Buchenau), Omnace^ (Petersen), Centrolepidacea 

 (Hieronymus), Comraelinaceae (Schonland), Conifers (Eichler, Engler, 

 Prantl), Cordaitacere (Engl er), Cycadacese (Eichler, Engler, Prantl), Cy- 



nrinHrn^VMn.^'-p V* H °UGHTON.--The development of Pilularia globulifera L. [Re- 

 print from Annals of Botany, Nov. 1888, pp. 233-204, with three plates.] 



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Englliiiann 1889^ * VoIlbllder ». sovvie AbU-iiim^-Uegistern Leipzig: Wilhelm 



