240 The Anatomy of Plants BOOK n 



subsequent fertilization and embryogeny. Bruchmann 

 also studied the formation of the embryo in 1874. In 

 the latter year Braun investigated the arrangement of 

 the leaves and the development of the branches of Sela- 

 ginella and of Lycopodium. The anatomy of the vege- 

 tative organs had not so far received much attention, but 

 about 1872 the subject was taken up by Russow, who was 

 followed in 1873 by Strasburger, in 1874 by Hegelmaier, and 

 in 1877 by Treub, all of whom investigated it with more 

 or less completeness in different species. The embryology 

 was further studied by Kienitz-Gerloff in 1881, and in 1885 

 Belajeff took up the investigation of the male gametophyte, 

 antheridia and spermatozoids, a more complete research on 

 the same lines being conducted by Campbell in 1895. The 

 most complete and comprehensive study of the anatomy 

 of the genus Selaginella was carried out by Harvey Gibson 

 in the years 1893-7. Though all parts of the plant had 

 not been examined by him before the close of the century, 

 his memoirs form a most valuable monograph of the whole 

 genus. 



The anatomy of Isoetes was examined in Russow's great 

 research of 1872, which has already been alluded to. The 

 development of the spores was studied by Tschistiakoff in 

 1873. Bruchmann investigated the development of the 

 root in 1874. The work of Goebel and of Bower on the 

 sporangia forms part of their memoirs on the general sub- 

 ject. In 1890 Farmer reinvestigated the structure of the 

 sporophyte and studied the embryogeny. Campbell also 

 conducted a research on the latter subject in the same 

 year. 



The early researches of Hofmeister and Cramer on 

 the Equisetaceae were followed in 1867 by the memoir 

 published by Pfitzer on the anatomy of several of the 

 German species of Equisetum. Janczewski and Famintzin 

 independently investigated their structure in 1876 and 



