9 o 



HARBWICKE'S SCIENCE-GOSSIP. 



you will hear from me again." Mr. Southwell's 

 communication with regard to the broods of young 

 birds seen on the Hickling Broads is of much 

 interest, and, as he says, this evidence lends support 

 to Mr. Fowler's discovery. — Joseph Anderson, Jim., 

 Chichester. 



MICROSCOPY. 



Scum at the Pilot Station, Saugor. — On the 

 8th January last, .a bucket of sea-water was sent to 

 me, in order that I might examine "some curious 

 things contained in it." Saugor is at the mouth of 

 the Hooghly, the river on which this city stands ; 

 and it is about eighty miles from here. The "curious 

 things " were hollow, spherical organisms, of a 

 greenish and greenish-yellow colour, eminently 



<Zt> 



% 





a©' 



^4\ 



Fig. 50. 



Fig. 49. 



Chlorophyll bodies from the membrane of the "scum" globules. 

 A, Seibert's jj in. w. i. ; b, Student's J. 



suggestive of grapes in general appearance. They 

 were filled with sea-water. Lifted out of the water, 

 they collapsed like bubbles, leaving only a thin, 

 greenish film on the hand, or glass. I placed one in 

 a beaker with sea-water, and gently let fresh water 

 into the vessel from a tap, until the whole of the salt 

 water was displaced. This caused the sphere to 

 grow flaccid ; but in the course of about thirty-six 

 hours it resumed its normal form, though it was now 

 paler in colour, and eventually became a dirty white. 

 The globules varied from about three-quarters of an 

 inch to half that size in diameter. From information 

 obtained by me from persons who observed the scum, 

 I gather that the stuff floated from six to nine inches 

 below the surface, that it extended over several miles 

 of surface, and was of some depth ; it was so dense 

 in parts that the water seemed nearly black ; when 

 first gathered it had a fine bright, but rather light- 

 brownish or yellowish colour ; the shades of colour 

 in the scum as it floated in the water varied; the 

 darker-coloured specimens were at the surface, sinking 

 when they got lighter-coloured ; that the natives and 

 fishermen in the creeks of the adjacent (Soonderbun) 

 country, say the scum breeds in the grass and jungle 

 which grow in the water on the banks of the creeks, 

 and thence floats away with the tide, though the 

 person who told me this added that he doubted if it 



was so, because the gelatinous-looking scum was far 

 more abundant in the open water of the sea and river 

 between the Sandheads (Saugor) and Diamond Har- 

 bour than it was anywhere in or near the creeks ; 

 and that it has been noticed in small patches in 

 previous seasons, but never in such enormous quanti- 

 ties as it was this year. The scum has always been 

 regarded as a fish-spawn ; it was supposed to be that 

 of the cat-fish. The batch sent to me, including the 

 specimen removed as above-described to fresh water, 

 remained intact for about three weeks ; on the 

 morning of the 28th January all the glassy spheres 

 had collapsed, and only a thin, dirty-green scum lay 

 at the bottom of the vessels in which I had placed 

 the stuff. Examined under the microscope, I found 

 numerous chlorophyll bodies embedded in a delicate, 

 hyaline, gelatinous membrane (matrix), which forms 

 the sphere, and which is all that remains when the 

 globules are removed from the water, and collapse. 

 An idea of the general appearance of these chlorophyll 

 bodies may be obtained by reference to PI. 5> fig- 5 

 {Apiocystis Brauniand) in the " Micrographic Dic- 

 tionary." These bodies readily take a deep stain if 

 roseine is used, while the membrane is but slightly 

 tinted ; I cannot say that anything is gained by 

 staining them. They are about -^ of an inch in 

 length, and t^ in breadth. It seems to me that the 

 organism is allied to the Nostocs, and that it is 

 probably only an intermediate life-stage in the de- 

 velopment of some other form. The question remains 

 — what is it ? Several to whom the matter has been 

 referred here have been unable to throw any light on 

 the subject, though they are agreed as to the vegeta- 

 ble character of the gelatinous-looking spheres. Will 

 any of your numerous and widely-scattered readers 

 tell us something about the scum over which we have 

 been puzzling our heads ? — W. J. Simmons, Calcutta. 



The Royal Microscopical Society. — The last 

 Journal of the above society contains the following 

 papers, in addition to the summary of current re- 

 searches relating to zoology and botany : — " Further 

 Notes on the Monochromatic Illuminating Appa- 

 ratus," by E. M. Nelson; and "Freshwater Alga; 

 and Schizophyceae of South-West Surrey," by A. W. 

 Bennett. 



The Quekett Club. — The last number of the 

 " Quekett Journal " contains the following papers : — 

 " On Notops Minor," by C. Rousselet ; " On a New 

 Cysticercus and a New Tape-Worm," by F. B. 

 Rossiter; "On Two New Rotifers," and "On the 

 Sense of Vision in Rotifers," by C. Rousselet ; " On 

 Two Undescribed Male Rotifers," by G. Western ; 

 "Further Note on the Sense of Vision in Rotifers," 

 by C. Rousselet; "On Two Rotifers from Epping 

 Forest," by F. A. Parsons; "On the Diffraction 

 Theory of Microscopic Vision," by E. M. Nelson ; 

 "On Mounting Media of High Refractive Indices," 

 by J. E. Ingpen. 



