494 THE UNIVERSE. 



further in order to insure the reproduction of plants when 

 the sexes reside each in a separate flower, and sometimes 

 on plants separated by a great distance. The corollas 

 Avitli stamens produce an enormous quantity of pollen 

 dust, which makes np for the difficulty of communication. 

 This strikes every observer who is in the neighbourhood 

 of a pine-forest. The pollen is often borne away from the 

 trees in such abundance that it covers all the surrounding 

 country with its yellow dust. This is the phenomenon 

 known by the name of "sulj^hur-rain." And indeed, 

 owing to its yellow colour and the Avay in which it burns 

 with a bright flame, pollen has been thought akin to sulphur 

 by some inexperienced observers. Sometimes, when it 

 falls upon the roofs of the neighbouring towns, it tints 

 them all over with a pale yellow.^ 



At the moment when the curtains of the nuptial couch 

 are opened the plants appear to suffer a febrile excitement. 

 Unwonted movements are observed in their floral organs, 

 and the temperature is sometimes raised in a very remark- 

 able manner. It seems, as the physiologist Burdach says, 

 that at such moments the plant issues from its humble 



ing of its investments, and thus comes in contact with the nucleus and embryo- 

 sac. In this sac there are at the top some minute vesicles called the germinal 

 vesicles, one or sometimes two of which, under contact, lengthen out into a 

 slender cellular thread, and at one end of this thread is the embiyo-plant. — The 

 Life of a Seed, by Slaxwell T. Masters, M.D.— Te. 



1 This phenomenon has been occasionally observed in the towns near the 

 landes of Bordeaux. The pollen of the pine-trees, borue by the wind, sometimes 

 stains all the roofs of a yellow colour. Pollen showers are not rare. The 

 learned are acr^uainted witli a great number of them. A very remarkable one 

 fell at Plcton in the United States in 1841. When Mr. J. W. Bailey submitted 

 its fine microscopic dust to the microscope, it was found to be entirely composed 

 of pine pollen. Another, which covered Troy and its environs, was discovered to 

 owe its origin to the same tree. The flames which issue at our theatres from the 

 torches of fairies or at conflagrations are due to the combustion of the inflammable 

 pollen of a little plant analogous to mosses, the Lycopodium olavatum, which is 

 collected bv means of bags. 



