142 BOTANICAL NOTES, NOTICES, AND QUERIES. 
and especially in the neighbourhood of London. Our Natural History 
Societies sometimes attempt more than they can achieve, and run the risk 
of perishing for want of funds. A field association, agreeing to meet near 
some railway station at stated times, pledged to nothing but to meet and 
herborize, geologize, or entomologize in the neighbourhood, and then re- 
turn, each member to his dwelling, would not be an expensive affair. Yet 
this would be productive of much good, not merely to science, but to the 
progress of humanity—a still more comprehensive and honourable object. 
Tt is true that we have societies enough in London, where we can meet and 
talk about science, and get acquainted with each other, and with ourselves 
too. But scientific etiquette lays some restrictions on our intercourse even 
here, which a rural excursion would in some measure remove. 
Dr. Johnston was fully as eminent in other sciences as in that to which 
we are limited. His treatises on the British Zoophytes, of which there have 
been two editions,—the first in one volume, the second in two,—and his 
History of British Sponges and Lithophytes, are regarded by the authori- 
ties on such subjects as standard works. We believe he was also the ~ 
Secretary of the Ray Society, at least on its formation and during the first 
years of its existence. His civic duties as Mayor of Berwick were not 
inconsiderable, and this honourable office he filled with. much credit to 
himself and gratification to the community ; and his urbanity and diligence 
were gratefully acknowledged by those who honoured him with their con- 
fidence and support. He was indeed a man of great labours (viz. magne 
laboris), and has bequeathed to posterity many testimonies of his talent, 
sympathy, geniality, and scientific merits. His life was an illustration of 
the almost proverbial saying, that the more a man devotes himself to his 
profession, or bread-study as the Germans call it (Brodstudiwm), the more 
leisure he finds for pursuits of a secondary nature. 
The practice of a medical man is, under any circumstances, very en- 
erossing and very laborious ; but most som the country, and particularly so 
in such counties as Northumberland and Berwickshire, the theatre of Dr. 
Johnston’s professional labours. With all these professional, civic (he was 
twice Mayor of Berwick), and domestic cares, the subject of this brief 
notice found time to teach his contemporaries and posterity sound know- 
ledge on the natural history of all the living beings, whether plants or 
animals, produced either on land or sea, in the district of country with 
which he was professionally or socially connected ; and erected for himself 
a far more durable monument than the work of the sculptor, though em- 
bodied in the choicest Parian. Exegit monumentum perennius ere. 
BOTANICAL NOTES, NOTICES, AND QUERIES. 
LINNEAN SOCIETY. 
Extract from a Memoir on the Origin and Development of Vessels in 
Monocotyledonous and Dicotyledonous plants, by Dr. F. F. Allemao, of 
Rio Janeiro, translated and communicated by J. Miers, Esq.—In a note 
to this paper, the translator observes that Dr. Allemio, of Rio Janeiro, in 
making his observations, was desirous of testing the validity of the theory 
suggested by Du Petit Thouars, and more recently modified and supported 
