covered with a cold and bright mantle of snow ; of these species which survive the winter, 

 some are biennial, and others perennial ; and, with respect to the former species, though 

 their life may be prolonged by transplanting them, and thus retarding the period of their 

 flowering and bearing seed, yet no artificial means can prevent their decay, after they have 

 provided for the future propagation of their species, by exercising this important function : — 



" He marks the bounds which winter may not pass, 

 And blunts his pointed fury ; in its case, 

 Russet and rude, folds up the tender germ 

 Uniajured, with inimitable art ; 

 And, ere one flowery season fades and dies, 

 Designs the blooming wonders of the next." 



Certain fungi are believed to be connected with the process of fermentation. The 



curious circumstance that, in certain bake-houses, all the bread becomes ropy, and though 

 sometimes prevented from assuming this condition by repeated washings of the walls and 

 floor with chloride of lime, the evil is occasionally so obstinate as to prove the ruin of the 

 establishment, is probably dependent on this cause. Dutrochet believes that he witnessed 



the growth of a Penicillium from the globules of milk. We talk of, and admire very 



properly, the beautiful flowers of the air-plants grown in greenhouses, forgetting that nothing 

 can be more varied than the common lichens which grow so profusely on our fence rails, 

 rocks, and elsewhere, deriving their nourishment from the air, and assuming most curious 

 hygrometrical variations — some, of the richest golden yellow, others with tiny goblets, the 

 borders studded with crimson shields. In the tropics, they lay hold of evergreen leaves ; 

 their chosen climate is one that is temperate and moist ; aspects to the north or west are 

 their favorite resort, for they shun the rays of the noontide sun. They are met with to the 

 limits of eternal snow. With a good microscope, a student might pass his life in their 



study alone. From kelp (the product of a sea-weed) a useful article for the soap-boiler 



and glass-maker is produced, and sea-wracks (as they are called) thus take their place 

 among valuable vegetation ; their soda makes useful manures, and in medicine they are 

 occasionally employed. Their medical value seems to be owing to the presence of iodine, 

 which is known to be a powerful remedy in cases of goitre, &c. The burnt sponge formerly 

 administered, probably owed its eflScacy to the iodine it contained ; and it is a curious fact, 

 that the stems of a sea-weed are sold in the shops, and chewed by the inhabitants of South 

 America wherever goitre is prevalent, for the same purpose. This remedy is termed by 



them, Palo-coto (literally, Goitre-stick). Fungi, including mushrooms, have engaged the 



attention of various naturalists ; they are important either as food or as poison, or as para- 

 sites destructive of plants on which they grow. As food, tlie most valuable are the Agaricus 

 campestris, or common Mushroom, the various species of Helvella, or Morel, and the Truffle ; 

 but a considerable number of other kinds are used as food in various parts of the world, of 

 which a useful account will be found in De Candolle's excellent Essai sur les Propri^tis des 

 Plantes ; Persoon, Greville, and other authors, have found them a prolific topic. The decay 

 of fruit appears, in a great measure, to be produced by them. The Rhizomorpha (a spurious 

 genus) vegetates in dark mines, far from the light of day, and is remarkable for its plios- 

 jihorescent properties. In the coal mines in Saxony, the species are described as giving 

 tliose places the air of an enchanted castle ; the roof, walls, and pillars, are entirely covered 

 witli them, their beautiful light almost dazzling the eye, the light increasing with the tem- 



jierature of the mine. Dr. Gray says, in one of his essays, "no idea is more fallacious 



than that those who know a little of a science may be qualified to write elementary books 

 for those who know nothing. Those who have but a pittance of scientific knowledge had best 

 give God thanks, and make no boast of it ; and as for their writing, let that appear 

 there is no need of such vanity." Mr. Bateham gives a slashing review of Hooper's 



i^f^'- 



