1019 



Extracts from the ' Proceedings of the Linnean Society.^ 

 (Continued from page 859). 



On the Development of Ferns from their Spores ; by A. Henfrey, Esq. 



The author commences his paper by referring to the remarkable 

 discoveries published by Count Leszczyc-Suminski in 1848, and the 

 observations to which they have subsequently led on the part of 

 others ; which appear to necessitate important changes in our gene- 

 ral views of the reproduction of plants. He finds, however, that the 

 results of some of these later observations differ in many respects not 

 only from those of Suminski, but also among themselves ; and that 

 opinions are divided both as to the actuality of the most important 

 fact of all, viz. the process of impregnation, and as to the period and 

 circumstances of its occurrence. Under these circumstances he has 

 thought he would be performing a useful task in subjecting the ques- 

 tion to minute investigation, in the course of which he has carefully 

 traced the development entirely through its course from the spore to 

 the young leafy plant, applying every available means to clear up the 

 anatomical conditions in each stage of the progress. The drawings 

 which accompany the memoir were nearly all made by means of the 

 camera lucida eye-piece, so that they represent preparations actually 

 seen. 



The subject is treated of under three heads : the first section con- 

 taining the author's own observations ; the second, a critical exami- 

 nation of those of preceding authors ; and the third, a few remarks on 

 the general bearing of the results upon vegetable physiology. 



Under the first head, Mr. Henfrey describes first the prothallium, 

 and its mode of growth, enlargement and decay ; secondly, the anthe- 

 ridia, with their sperm-cells and spermatozoids ; thirdly, the arche- 

 gonia, with their papilla? and embryo-sacs ; and fourthly, he gives his 

 own view of the development of the embryo. On all these points he 

 enters into much detail, tracing the several stages of the process with 

 great minuteness. In his criticism of previous observations, he passes 

 in review the facts and opinions stated by Nageli, Suminski, Wigand, 

 Thuret, Hofmeister, Schacht, Mettenius, Von Mercklin, and Hofmeis- 

 ter again ; and indicates the points in which he himself either coin- 

 cides with or differs from each of them. The memoir is so completely 

 one of detail, that under these two principal divisions it would be dif- 

 ficult to give a sufficiently clear abstract without running to too great 



