HARDWICKE'S SCIENCE-GOSSIP. 



235 



the Nottingham Naturalists' Society. This paper, 

 which includes the classification of starches after Dr. 

 Muter, should be useful to microscopical botanists. 



Cole's Microscopical Studies. — The last- 

 received box of this series contains mounted and 

 labelled slides of lung, brown induration ; tracheal 

 system of silkworm ; horizontal section of gill of 

 Anodonta cygnea ; and vertical section of sorus of 

 scolopendrium. 



"The American Monthly Microscopical 

 Journal."— The August number of this journal 

 contains, among others, papers on Cleaning Marine 

 Mud, by Dr. G. H. Taylor ; and on Mr. Charles 

 Fasoldt's Detaching Nose-Piece for Rapidly Changing 

 Objectives (illustrated) ; and a continuation of the 

 translation of Professor Hans Gierke's notes on 

 Staining Tissues in Microscopy. 



Protoplasmic Movement. — Mr. Charles E. 

 Bessey states, in the " American Naturalist," that the 

 movement of protoplasm may be easily seen in the 

 "silky" styles of Indian corn. Care should, he 

 says, be taken to lay them flat, the styles being some- 

 what ribbon-shaped, not cylindrical. 



Bolton's Portfolio of Drawings. — The August 

 portfolio of this series contains a dozen or more 

 drawings to accompany the living specimens which 

 have been sent out by Mr. Thomas Bolton, of Bir- 

 mingham. The drawings, printed in black and 

 white, are very interesting, and show signs of great 

 care. Judged, as they are, apart from their speci- 

 mens, some of them especially seem to deserve great 

 praise ; and on the back of each may be found some 

 explanatory text. 



ZOOLOGY. 



Helix Aspersa and Aspera. — Mr. W. C. 

 Atkinson, pointing out a mistake on p. 1S8 of this 

 vol., by which H. aspera is printed for H. aspersa, 

 says that there is a Jamaica species, to which 

 Ferussac gave the name H. aspera, and observes that 

 it may be needful to note that the difference in the 

 spelling of these two very similar names indicates 

 the distinction between two very different species. 



E.HYTINA Stelleri.— In the " Geological Maga- 

 zine," Dr. H. Woodward has a paper on Fossil Sirenia 

 in the Natural History Museum. A nearly complete 

 skeleton of the recently extinct Rhytina Stelleri was 

 acquired for the museum during the early part of 

 the year. This animal, seen by Stellerin 1741, was 

 exterminated from Behring's Island and Copper 

 Island, to which it was then limited, over a hundred 

 years ago. Its bones are not found on the surface 

 of these islands, nor at the sea level, but in old 

 raised beaches and post-tertiary peat-mosses, and 



their presence is ascertained by boring into the peat 

 with an iron rod or some such tool. The skeleton 

 confirms Professor Brandt, who attributed to Rhy- 

 tina seven cervical vertebrae, the number usual in 

 mammalia. Steller, in 1741, observed these "sea- 

 cows " browsing in herds on the sea-weed in the 

 shallows along the shore. When full grown their 

 length is said to have sometimes reached thirty-five 

 feet, and their weight three or four. tons. 



"Pholas" (P. crispata). — Whilst watching the 

 animals in my aquarium one night, I was surprised 

 at the movements of the pholas (P. crispata). I 

 have three specimens, and as they are merely lying 

 upon some stones at the bottom of the aquarium, the 

 conditions are not quite natural for the borer. As 

 soon as the rays from the lamp fell upon the water, 

 the pholades quickly turned their siphons towards the 

 light, even so far as to bend the siphonal tube when 

 the light was placed at right angles to the end of the 

 siphons. When first bringing the light into a dark 

 room, the P. crispata is very sensitive to it, and 

 brings the end of its tube in a line with the direction 

 of the lamp ; but, after some short time, it takes no 

 further notice, unless the light be concentrated, a 

 little to its right or left, when it slowly turns the 

 point of the siphon to the side that the light falls 

 upon. In looking up the pholas in a number of 

 works, I find no mention of eyes, not even that 

 it is sensitive to light. In a small work on the 

 "Common Shells of the Sea Shore," by the Rev. 

 J. G. Wood, there it is stated that "on the inside of 

 the hinge of the pholas is seen a curved projecting 

 piece of shell, the use of which seems to be rather 

 obscure." This statement led me to look for the 

 projecting piece of shell mentioned by Mr. Wood. 

 And on opening the pholas, a very beautiful modi- 

 fication of the usual hinge presented itself, in the 

 form of a pair of hooks, one on the inside of each 

 valve. The hooks are imbedded in the animal, and 

 enable it to bring the shell close to its body when 

 the siphons are extended, and to force the shell 

 asunder when they are contracted, thus allowing a 

 greater amount of freedom to the movements of the 

 siphons. Without the hook-like hinge, or with any 

 other form of attachment, it would be impossible for 

 the pholas to bring its siphons within the valves. 

 When the siphons are withdrawn into the shell, the 

 valves gape considerably, and are quite apart ; but 

 when the siphons are extended the valves are brought 

 together again simply by this hook-like hinge, if so 

 we may call it, the ordinary muscular attachment 

 has very little power over this posterior gape. I 

 shall be glad to hear from some of ours. — P. H. 

 Marrow. 



Axolotls. — Would E. T. D., Crouch End, kindly 

 tell Dr. Willett, Bristol, where he could obtain the 

 axolotls he wrote of in the August number of Science- 

 Gossip ? 



