ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 99 



B. CRYPTOGAMIA. 



Cryptogamia Vascularia. 



Apospory in Ferns.* — W. T. Thiselton Dyer calls attention to a 

 paper by Mr. E. T. Druery (not yet published) as containing a report 

 of one of the most interesting botanical observations which has been 

 made for some time. 



Mr. Druery's paper relates to a singular mode of reproduction in 

 Aihyrium Filix-fcemina var. clarissima. In this fern the sporangia do 

 not follow their ordinary course of development, but, assuming a more 

 vegetative character, develope more or less well-defined prothallia, 

 which ultimately bear archegonia and antheridia. Prom these ad- 

 ventitious prothallia the production of seedling ferns of a new 

 generation has been observed to take place in a perfectly normal 

 way. 



Mr. F, 0. Bower has confirmed Mr. Druery's observations, and 

 obtained from him specimens of another fern {Polystichum angulare 

 var. pulcherrima) which altogether eclipses the Atliyrium, remarkable 

 as that is. In the Polystichum the apex of the pinnules grows out 

 into an irregular prothallium, upon which was demonstrated the 

 existence of characteristic archegonia and antheridia. In this case 

 the production of the prothallium is not even associated locally with 

 the sporangia, but it appears as a direct vegetative outgrowth of the 

 normal spore-bearing plant. The oophore is a mere vegetative 

 process of the sporophore, a suppression of the alternation of the 

 two generations which exceeds even that which obtains in the 

 flowering plant. 



Mr. Druery's discovery is the direct converse of the apogamy in 

 the fern, discovered by Farlow. In this the sporophore is a vegetative 

 outgrowth from the oophore. The parallel phenomena in the life- 

 history of the moss have been known for some time. The obvious 

 possibilities of discovery with regard to the reproduction of ferns may 

 now be regarded as exhausted. It may be interesting to give the 

 dates of the different steps : — 



1597 Gerarde .. Observed seedling plants near parents. 



1648 Oaesius .. Sporangia. 



1669 Cole .. .. Spores. 



1686 Eay .. .. Hygroscopic movements of sporangia. 



1715 Morison . . Kaised seedlings from spores, 



1788 Ehrhart .. Prothallium. 



1789 Lindsay . . Germination of spores. 



1827 Kaulfuss .. Development of prothallium. 



1844 Nageli .. .. Antheridia. 



1846 Suminski .. Archegonia. 



1874 Farlow . . . . Apogamy. 



1884 Druery ., .. Apospory. 



Stomata of Equisetum.t — Miss E. A. South worth gives the fol- 

 lowing account of observations on the stomata of Equisetum arvense 



* Nature, xxxi. (1884) pp. 151 and 216. See also p. 119. 

 t Amer. Naturalist, xviii. (1884) pp. 1041-2 (1 p].). 



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