REARING OYSTERS. 455 
boundless hospitality with which we were everywhere received 
by the hospitable people of New Zealand. 
Elevation, in 
NAME OF PLANT, AND AUTHORITY, fond ae Station 
5 ; 
Ranunculus sericophyllus (Armstrong) - - - 6400 
Ligusticum aromaticum (Hooker, fil.) - - - 6400 
Flectorella cespitosa (Hooker, fil.) - - - 6400 
Raoulia grandiflora (Hooker, fil.,.and Armstrong) 6400 
Hlaastia greeni (Hooker, fil.) - - - - 6500 
Gnaphalium grandiceps (Armstrong) - - - 3—5000 
Gnaphalium bellidioides (Armstrong) - » : 3—4.000 
Helophylium colensot (Hooker, fil.) - - - = 
Dracophyllum rosmarinifolium (dwarf) (Armstrong) — 
Coprosma pumila (dwarf) (Armstrong) - - - 6500 
Euphrasia ( ?) - - : ‘ 2 is i Cal, 
Celmisia sessiliflora - - E 4 2 3 6400 
REARING OYSTERS FROM ARTIFICIALLY- 
IMPREGNATED EGGS.* 
———.-_ >> 
BY J. A. RYDER 
Pee EO ie 
During the past three years the writer has been engaged 
upon the investigation of this subject, with the view of reaching 
some practical results which would be available in the hands of 
oyster-culturists. Until last year his efforts under the auspices 
of the U.S. Fish Commission had been comparatively fruitless 
and unsatisfactory. In July and August last, in association with 
Col. M. McDonald, the experimental work was resumed at St. 
Jeromes Creek, St. Mary’s County, Maryland. Col. McDonald 
devised a simple combination of glass apparatus, consisting of a 
series of jars connected together with rubber tubing, somewhat in 
the manner of a series of Wolft’s bottles, with an open glass aqua- 
rium at a higher level as a feeder or reservoir, while the last jar 
of the series discharged into a similar cylindrical aquarium stand- 
ing on the floor. ‘The sea-water introduced into this contrivance 
was carefully filtered through cotton-wool, to remove all sedi- 
ment and foreign organisms. The circulation was maintained 
in this contrivance by baling the water from the lower into the 
upper aquarium ; the water passing continually through the in- 
tervening series of jars, which were, in effect, simply enlarged 
portions of the siphon-tube passing from the upper to the lower 
aquarium. No difficulty was experienced in keeping the water 
in this apparatus fresh and sweet without renewal. 
On the 23rd of July a batch of oyster-eggs was introduced 
into this apparatus, impregnated by a method to be hereafter 
described. On the 24th, and just about 24 hours after impreg- 
nation had taken place, an inspection of the transparent sides of 
the jars and aquarium was made ; and, to our great surprise, w 
* Extracted from ** Science,” vol, tp, 52. 
