The Germination of Fern Sjpores. 33 



29th. number of the Intellectual Observer (for June, 1864), 

 from the pen of Mr. R. Dawson, M.B., wherein, amongst a 

 good deal that was interesting and instructive, certain state- 

 ments were put forth by that writer which certainly demand 

 a few words by way of reply. 



But, first, as to the method of observing the phenomena in 

 question. 



Having provided oneself with one or more of the round 

 shallow glass troughs, with bell-glasses to match, such as are 

 manufactured at a very reasonable cost by Messrs. Claudet and 

 Houghton, of 89, High Holborn (and called by them propa- 

 gating glasses), let the troughs be filled about an inch or so 

 deep with clean river-sand. If sea-sand be employed it must 

 be scrupulously cleansed by repeated washings in spring 

 water, to get rid of the salt. Next, having prepared as many 

 small lumps of porous sandstone, each about 1-^ inches square, as 

 you wish to have species of ferns, and having conspicuously 

 scratched a number on each (Roman numerals are perhaps 

 most convenient) for the purpose of identifying your future 

 plants, flip them in clean spring water, and place them on a 

 table which is not exposed to a draught. Then sprinkle sepa- 

 rately a very small quantity of fern spores on each of your 

 pieces of sandstone — having, of course, previously collected 

 the spores by placing a portion of the mature fronds, whilst 

 in fructification, between separate sheets of note-paper, and 

 preserving the spore dust which will be discharged from 

 them. 



Great care is requisite in order to prevent the mingling of 

 the extremely light and almost invisible spores ; and it is ex- 

 pedient to open only one packet at a time, dipping a separate 

 small feather, or morsel of paper, into one packet after 

 another, and gently rubbing therewith the upper surface of 

 your pieces of sandstone ; and, as another precautionary step, 

 it is moreover rather desirable that the stones should be 

 freshly fractured, or at least the surfaces rubbed to a new 

 face, as sporules of various kinds of mosses, Marchantice, etc., 

 are very apt to establish themselves upon fragments of stone 

 picked up at hap-hazard by the wayside. 



Then saturate the river-sand in your troughs with spring 

 water, till it is of about the humidity of mortar, arrange your 

 pieces of stone thereupon, so as you can most conveniently 

 see the numbers, a list of which, specifying the different kinds 

 of ferns, date of sowing, etc., may be advantageously pasted 

 outside your bell-glass for reference. 



Place the glasses in a tolerably warm room or greenhouse, 

 but where they will not be exposed at any time to the direct 

 rays of the sun, and after a few days or weeks (according 

 VOL. VII. — NO. i. D 



