1857.] REVIEWS. 187 



will upset another of our time-hallowed fictions, viz. that winged 

 seeds are more dispersable or occupy larger tracts than seeds un- 

 provided with these singular appendages. "Among the Compo- 

 sit(B the proportion is as 4*5 to 2*9 per cent, in favour of naked 

 seeds (seeds without down or wings), and hence the Daisy is 

 twice as diffusable as the Dandelion and the Thistle." There are 

 however other causes which contribute to the distribution of 

 plants over and above the media by which they are conveyable 

 from the places where they grow to remote localities. One of 

 the most important of these is the mechanical condition of the 

 soil as pulverized or not, and another is atmospheric ; but there 

 is not room to illustrate these causes here. 



The rapid dissemination of American plants in Europe and 

 even in England, and the spread of European and other plants 

 in the agrarial and even pastoral districts of Britain, has often 

 been noticed. At the same time but little or at most less atten- 

 tion has been paid to the transmission of our own familiar spe- 

 cies to other lands. ' Our author informs us that the Great or 

 Horse Daisy is common in America, and a more troublesome 

 weed than it is here. The Thistles of Europe are so formidable 

 in Australia that the legislature has been induced to impose pe- 

 nalties on their non-extirpation Uleoc europmus, the common 

 Whin^ has emigrated to Van Diemen^s Land and St. Helena, 

 where it abundantly increases. We are indebted to America for 

 one at least of our Balsams, Imp aliens fulv a, for Erigeron cana- 

 densis, Anacharis Alsinastrum, Mimulus luteus, (Enothera bien- 

 nis, etc. etc., and we repay our obligations by the export of our 

 Thistles and other agrarial plants. 



We havie not much confidence in the fact observed, it is said, 

 by one of the moderns, that Wheat is derived from jEgilops, and 

 that Rye and Oats are only different or accidental states of the 

 same species. These facts, if facts they be, might easily be veri- 

 fied by thousands of moderns who are all, more or less, cupidi rerum 

 novarum, " fond of novelty." The fact that the widely dispersed 

 species may owe their extended range to their having an earlier 

 date in creation is not so capable of proof. 



The readers of the ' Phytologist,' such of them as have not 

 seen the elaborate work in question, are indebted to the editors 

 of the 'Natural History Review^ for this extended notice, which is 

 exclusively borrowed from their April number (1857). But as 



