194 
NOTES AND MEMORANDA'. 
The eggs of the large infusoria are rare. Rain-water introduced 
with the greatest precautions into flasks (having their necks drawn 
out and sealed) rarely encloses rotifers, cyclops, keronae, loxodes, &c., 
but bacteria are always found, very often monads, and sometimes 
rhizopods. On the other hand, 40 cubic metres of the dust, immersed 
in water freed from all germs, habitually give many species of largo 
infusoria, although it may be difficult to recognize at once their eggs 
amongst the millions of germs in which they are distributed. 
The cellules which arc most diffused in the air are undoubtedly 
the spores of the Mucedinre and of numerous cryptogamic productions, 
whose diameter varies from o' ^ millimetre. Then come 
the fructifications of certain fungi whose dimensions, more considerable, 
sometimes reach y^y of a millimetre. I refer to those septate bodies 
or germinativc masses swollen up in the form of spindles, gourds, 
or clubs. Then come pollens of very variable size and colour, then 
grains of starch, which are to the other matters as 1 to 100 or there- 
about, and lastly the green algae which the air transports sometimes in 
voluminous quantities. 
The author concludes by pointing out that it would perhaps be 
useful and interesting, as bearing on questions of public hygiene, to 
extend to the corpuscles of the vibrions this kind of statistical study.'^ 
The Foraminifera and Pohjcystina of the North Polar Expedition of 
1875-76. — Mr. H. B. Brady, F.R.S., describes in the ‘Annals and 
Mag. of Nat. Hist.’ for June, the results of his examination of the 
soundings from depths of 10 to 220 fathoms brought home by the 
expedition. After stating that the area represented by the collection 
is altogether new, the author says that there are about half-a-dozen 
species of Foraminifera that may be regarded as essential consti- 
tuents of the microzoic fauna of these high latitudes, having been 
found at almost every depth at which the floor of the sea has 
been examined. They are, Glohigerina hulloides (a dwarf variety), 
CassiduUna laevigata and G. crassa, Truncatulina lohatula, Pulvinulina 
Karsteni, and Polijstomella striatopwictata, usually accompanied by 
one or two forms of Nonionina, varying according to depth and other 
circumstances, and, if the sea-bottom be composed of rough sand or 
gravel, by Polijstomella arctica. Other species occur in every sample 
of mud or sand, wherever obtained ; but it is not too much to say 
that those above enumerated constiHite ninety-five per cent, of the 
entire collection made from these soundings. The constant occurrence 
of CassiduUna laevigata, of full size and well grown, even when the 
other Foraminifera accompanying it were poor, starved specimens, 
and the presence of Pulvinulina Karsteni in almost every dredging, to 
the practical exclusion of all other species of the same genus, are 
points of considerable significance. The almost complete absence of 
the Milioline genera (for the occurrence of a single, minute, thin- 
shelled specimen here and there in a few of the soundings amounts 
to absence in such a case) is an unexpected feature. In dredgings at 
similar depths but little to the south of those under consideration 
* ‘ Comptes Rendus,’ vol. Ixxxvi. p. 1552. 
