eos OYSTER CULTIVATION IN THE NETHERLANDS. 1011 
and temperature, the distribution of the larve in the water is a question 
of primary importance. 
“Tt was a grievous disappointment to me that I had to let the greater 
portion of the month of July go by without making any observations 
in this direction; and as the weather during August was exceptionally 
unfavorable, I could not make up for time lostin July. Spat fell during 
all of this month, but regular observations at favorable points had be- 
come absolutely impossible. During the coming summer I hope to be 
able to devote my undivided attention to the distribution of the oyster 
larvee.” : 
On the PHYS[CO-METEOROLOGICAL OBSERVATIONS in the Eastern 
Scheldt during 1831, the following report was offered by Mr. Hubrecht, 
who had been assisted in his work by Mr. van Kervel: 
As soon as possible after the Commission of the Zoological Station had, 
at their meeting of March 10, resolved that the observations of the 
oyster cultivation (and subjects connected therewith) in the Eastern 
Scheldt, should also be extended to the condition of the water, its tem- 
perature and density, as well as the nature of the currents in the Scheldt, 
which might exercise an influence on oyster cultivation, the commission’ 
opened negotiations with Prof. C. H. D. Buys Ballot, of Utrecht, Director 
of the Meteorological Institute. To his kind aidand the friendly assist- 
ance of Dr. Maurits Snellen we owe the knowledge of various impor- 
tant facts as to the best manner and time of taking observations, and 
of a peculiarly arranged areometer, which was manufactured under the 
supervision of Dr. Maurits Snellen, and which deserves the preference 
over other areometers which we tried. To these gentlemen we herewith 
express our best thanks. 
From the very beginning we felt convinced that, on entering a field 
in which none of our number felt at home, we ran great risk of making 
mistakes and of drawing erroneous conclusions, if we did not eall in the 
aid of competent persons at the right time. It soon became evident 
that the observations on the current would not only require theoretical 
knowledge and technical experience which we did not possess, but 
would also involve considerable expense, which our treasury was not 
able to bear. These difficulties, however, would only deter us from 
making the desired observations if if should appear that we could not 
have the help of competent persons. Our hope that the minister of 
public works would allow the expenses of these observations to be borne 
by his department was not put to shame, and by a letter from him, 
under date of August 26, 1881, we were authorized to enter into. an 
arrangement with the chief engineer of Zealand. Thanks to the kind 
assistance of this officer and of the district engineers stationed at Goes 
and Zierikzee, we had a preliminary conference on the subject, where we 
kad an opportunity to state the ideas which led us to the supposition 
that there must be some connection between the settling of the oyster 
