FERTILISATION AND PROPAGATION. 



Ill 



that, through its being subjected to different conditions as regards "food," 

 temperature, &c, two or three varied forms of asexual spores are found on a 

 plant, Taken generally, the spores of Cryptogams, through the reproductive 

 phenomena which they present to the observation of the botanical student, 

 may rightly be considered as amongst the most wonderful subjects to which 

 his attention may be devoted. Their microscopical nature also affords the 

 greatest contrast between their diminutive size and the gigantic dimensions 

 attained by some of their produce. 



Mr. Charles T. Druery, in his excellent work on "Choice British Ferns,"* 

 has a remarkable chapter devoted to "The Wonders of the Spore," which is 

 undoubtedly the result of an extensive series of personal and careful obser- 

 vations, and which, treating as it does at length on the minuteness, the 

 fertility, &c, of the subject, we cannot do better than quote here without 

 unnecessary comments. As illustrating the great contrast between the spore 

 and its results, Mr. Druery says : " Take, for instance, the largest of the Tree 

 Ferns : here we have nothing less than a noble, stately tree, possibly 100ft. in 

 height, with a huge, spreading crown and massive trunk in proportion, the 

 whole of which has been developed from a microscopic spore, invisible to the 

 naked eye. If we examine the fronds of that huge tree, we shall probably find 

 the backs entirely covered with small, brown patches, lines, or dots, of which 

 there will be countless myriads upon a single frond ; yet, notwithstanding 

 their number, every patch, line, or dot will, under the microscope, resolve 

 itself into not merely a heap of spores, but into a heap of hundreds of capsules, 

 or pods, each of which in its turn, though itself barely visible, contains some 

 forty or fifty spores. Hence, there are many thousands of spores in every 

 patch, or myriads of millions on every frond, every individual of which 

 is capable of reproducing the parent form in all its luxuriant and stately 

 magnificence. 



" To bring this illustration of fecundity home to the mind, we have 

 estimated the spores upon a single frond of our native common Polypody 

 (Polypodium vulgar e), and found that one of the subdivisions of the same 

 size, taken from a Tree Fern, would yield plants sufficient to form a wood as 

 large as Epping Forest. Every frond would bear hundreds of such sub- 



* "Choice British Ferns." By Charles T. Druery, F.L.S. Illustrated. London: L. Upcott Gill, 

 170, Strand, W.C. 



