1876.] Aquaria: Their Past, Present, and Future. 611 
imens of which may always be recognized by their pale color. 
In Europe, the caterpillar is infested by the larve of a Microgas- 
ter ; parasites reared by me perforated the skin of the caterpillar 
August 19th and made their cocoon on its body. September 4th 
the box containing the cocoons was opened, disclosing both dead 
_. and living imagines ; they belonged to two distinct species, those - 
of the smaller being dead and dry, while those of the larger were 
either living or recently dead; on the succeeding day the re- 
mainder of the larger ones appeared, and proved to be, as iden- 
tified by my friend Mr. Drewsen, of Copenhagen, Microgaster sub- 
completus var.? von Esenb., and the smaller an undetermined 
species of the same genus, probably undescribed. Of the former 
3¢ and 15? emerged ; of the latter 8¢ 3? ; besides these, four 
larve had been taken from their cocoons and preserved in that 
state ; all of these came from the body of a single caterpillar. 
The larger species is probably the actual parasite of V. cardui ; 
the latter, a parasite of the parasite. 
AQUARIA: THEIR PAST, PRESENT, AND FUTURE. 
BY WILLIAM ALFORD LLOYD. 
[ilGuty-srx years ago — in the year 1790 — there might 
have been seen trudging along the streets of Edinburgh an 
“old blue-coated serving-man,” carrying an earthenware pitcher 
or jar, of three or four gallons’ capacity That pitcher contained 
sea-water for the marine aquarium of Sir John Graham Dalyell, 
Bart., who thus employed a man, or probably a succession of 
men, from the time he began aquarium-keeping till he finished 
at his death in 1851, a period of sixty-one years. The jar was 
sent to the sea to be filled twice or thrice weekly ; but averaging 
itat five times a fortnight, and allowing four miles for each double 
journey from Great King Street to the sea and back, that 
‘mounted to 39,650 miles from the year 1790 to the year 1850, 
which was an enormous and perfectly needless expenditure of 
force, expressed in time and money, even although the results of 
ir John’s investigations were given to the world in five such im- 
Portant quarto volumes as his Rare and Remarkable Animals 
of Scotland, 1847-48 ; and his Powers of the Creator displayed 
ìn the Creation, 1851-58. 
Dalyell’s mode of operation, as told to me by his sister Eliza- 
h, in two letters dated 1860, and printed in the Zoölogist of 
