Sune 16, 1870] 
NATURE 
E35 
ing the decimal mode of division to the quadrant of the circle 
and the quarter of the day, as proposed by M. D’Abbadie, the 
whole circle and the whole day should be taken as the unit 
of division. M. D’Abbadie remarked that the quadrant is the 
natural unit which has always been adopted for trigonometrical 
purposes, and indicated some practical inconveniences which 
would result from a change. Of the remaining communications 
only the titles are given. 
Boston 
Natural History Society, Section of Microscopy, Feb. 9.— 
Dr. B. Joy Jeffries inthe chair. The following paper was 
read :—‘* Notes on Diatomaces,” by Professor Arthur Mead 
Edwards. ‘*A few days since (Sept. 1869) I made a gathering 
in a ditch communicating with the salt water of the Hudson 
River, opposite the city of New York, at Weehawken, N. J. 
Of course the water in the ditch was salt, and, in fact, in it last 
spring Ihad caught specimens of Stickleback (Gasterosteus) 
which had come up there from the river to spawn, as is their wont 
todo. The Ten-spined Stickleback (G. fuzgitius) I had found 
yery plentiful, and mixed with it a few individuals of the Three- 
spined (G. acwz/eatus) ; in fact these fish occurred in such numbers 
that when the water became foul, as it did by evaporation, the 
bottom of the ditch was literally covered with their dead bodies. 
The gathering, however, I have to speak of at the present time was 
made for the purpose of procuring Diatomaceze, and consisted 
of specimens of an alga belonging to the genus Z7/eromorpha, 
having attached to it more or less firmly numerous Diatomaceze 
and animals. The commonest form of Diatom was a Cyclotella, 
and seemingly fixed in some manner to the Z7¢eromorpha, for it 
was not shaken off by pretty rough usage. How it was fixed I 
could not detect; most likely by means ofa mucous envelope of 
such tenuity that itis not readily seen. The next most common 
form is the truly wonderful, inexplicable Bacil/aria paradoxa, the 
paradoxical bundle of sticks. Often and often have I spent 
hours looking at this marvel of nature; the motion without 
apparent cause or mode, an invisible joint which, as a friend of 
mine, an engineer, once remarked, would be a fortune to any 
one who would discover it, for here we have several sticks form- 
ing the bundle, moving over each other without separating, and 
yet the use of the highest powers of the microscope has failed to 
detect the means of their union into one mass or composite group 
of individuals. This grouping of individuals together, which 
we so commonly find among the Diatomacez, as in Schzzonena, 
Achnanthes, Melosira, and a host of other genera, appears to 
me to have its analogue in the animal kingdom in the Polyzoa; 
which, although generally fixed, yet at certain periods throw off 
motile forms by means of which the species is distributed. Do 
not the Diatomacez do likewise? I am of opinion that they do, 
and I shall produce evidence on that point further on. As to 
the Bacillaria paradoxa, the oftener I watch it the more it 
puzzles me. Not long since I saw one specimen (of course I 
mean one bundle of individuals) slide out to its utmost limit 
across the field of view, and then, becoming entangled with two 
others, which likewise were made up of many individuals, some 
eight or ten of its frustules (as the complete individuals are 
called) were twisted around almost off from the rest, so as to 
lie at right angles to them, and when the group containing the 
largest number of frustules receded to their former position, 
which they soon did, the eight or ten seeming by the act of 
twisting to lose their power of motion among themselves for the 
time being, were dragged along in a helpless condition, and 
twisted completely around one revolution, so as thereafter to fall 
back again into their places, when all went on as usual. That is 
to say, the regular motion of all the frustules over each other 
succeeded. Now what kind of a joint can it be that permits of 
such eccentric movement? As I have already said, I am more 
puzzled than ever. Along with the Zaci/aria in the brackish 
water at Hoboken, I found numerous individuals of an Amfhcra, 
which I have known in this neighbourhood for many years, 
and which I considered unnamed as yet. To it I have given the 
provisional name of A. /anceolata, on account of the form of its 
outline. This genus has always been considered an epiphytaceous 
one ; that is to say, one which grows attached to other plants or 
submerged substances, yet this form was free and in active 
motion. In fact I think it was one of the most lively Diatoms I 
ever saw. So another small species of Ahora which is common 
near here, is always, as far as I have noticed, free. Here we 
have species appearing both in the free and attached conditions, 
and this is even morestrikingly illustrated in Schizonema, Bacil- 
aria paradoxa is usually set down as the most rapid in motion of 
the Diatomacez, its velocity being recorded by Smith, as he 
measured it, at over one two-hundredth of an inch in a second. 
This is certainly pretty quick when we consider that the length 
of the frustule is only ‘0025 of an inch. But my experience has 
been that its velocity varies in every degree from that mentioned 
to perfect rest ; at times some individuals will be in rapid move- 
ment, while others are motionless ; and also J have remarked that 
{from sunrise to noon seems to be the period during which, under 
ordinary conditions, the moyement is most active, while during the 
afternoon it is very sluggish, and at night almost 277. This Ame- 
Phora, as I saw itat the time mentioned, was moving even more 
rapidly than I ever sawa Lacil/aria move, and that with a steady 
onward progression very different from that of most naviculiform 
diatoms. Many months since I mentioned at one of the meetings 
of the Lyceum of Natural History in New York, that I had seen 
two apparently different genera of Diatoms existing within the 
same investing tube; and now I wish to place that fact upon 
record, and to state one or two more instances of the same mode 
of growth. During the month of March 1868, I found in the 
harbour of New York specimens of Schizonema Greville’ in active 
motion within their investing tubes, but accompanied by a much 
smaller form possessing a totally different outline from S. Greville, 
being blunter at the ends, and with parallel sides. During 
the same month, and also in April, I found this mode of 
occurrence very common, and also Schizonema Grevillei and a 
Homeocladia in the same tube, and Schizonema cruciger and the 
small form mentioned aboye, both in the same tube, and S. crzciger 
and Greville: in the same tube. In all these cases the frustules 
were in lively motion, passing over each other from one end to 
the other of the tube. In May of the present year, 1869, I found 
growing in the salt water of the ‘Mill pond’ at Salem, Mass., 
Schizonema cruciger and Nitzschia closterium, W. S. (Ceratoneis 
closterium, C. G. E., and Witeschiella closterium, L. R.), both in 
the same tube. And here it will be necessary to say something 
in regard to the form I have called N#tzschia closterium, as 1 
shall thereby, I hope, be enabled to clear away a little fog of 
synonyms, Neither Smith, Kiitzing, nor Rabenhorst describes 
or figures any species living within a tube like Schizonema, the 
frustules of which have an outline and markings similar to 
Niteschia closterium, so that it is not likely that they ever saw 
anything but the free form or condition of this species. How- 
ever, Ehrenberg figures and describes, under the designation of 
Schizonema? Agardhii (Die Lnfusionsthierchen, 1838, p- 343, te 
xx. fig. xvi.), a form agreeing with this, but the structure of the 
frustule is that of Ai/eschiella of Rabenhorst, so that the specific 
name of this species should be Agardhiit, whatever its genus be 
decided to be hereafter.” 
March 2.—Dr. C. T. Jackson, vice-president, in the chair. 
The following papers were presented :—‘‘ Description of the 
Larva and Chrysalis of Papilio Rutulus Boisd., of California,” 
by Samuel H. Scudder.—‘‘On the Phosphate Beds of South 
Carolina,” by N. S. Shaler. The latter contains a partial account 
of the observations made upon this district by the author, while in 
the employ of the United States Coast Survey, and is published 
with the permission of the Superintendent of the Survey, Prof. 
Benj. Pierce, of Cambridge. A portion of the conclusions have 
a certain commercial as well as scientific value, and it was deemed. 
by the Superintendent desirable to place them before the public 
at the earliest opportunity. The remainder of the description 
of these beds will be found in the report of the work of the Coast 
Survey for 1870. 
March 16.—Mr. William T. Brigham in the chair. The fol- 
lowing papers were presented :—‘‘ Note on the Occurrence of 
Luleptorhamphus longirostris on the Coast of Massachusetts,” by 
F, W. Putnam.—‘‘ Revision of the Classification of the Mollusca 
of Massachusetts,” by W. H. Dall, Smithsonian Institution. 
New York 
Lyceum of Natural History, Chemical Section, May 
g.—Prof. Charles A. Seely ‘On the Constitution of Am- 
moniacal Amalgam.” Ammonium amalgam was discovered by 
Berzelius in 1808 ; and immediately after by Pontin, Seebeck, 
and Trommsdorff. Its easy preparation, singular properties, and 
its relation to current theories, have made it familiar to all 
chemists. It led to the adoption of Ampere’s ammonium theory, 
gaye a great impetus to the theory of organic radicals, and 
revived the notions of the alchemists of the compound nature of 
metals. Early in this century it led many to conclude that the 
base of nitrogen is a metal ; and at the present time, without 
