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HA R D WI CKE 'S S CIENCE -GOSS IP. 



insect crawling along tlie road just outside what used 

 to be Coombe Wood. Stephens gives its time of 

 appearance as May to August, and I have never 

 previously observed it earlier than the third week in 

 April.— y. W. Slater. 



Testacellus haliotideus. — I have in my pos- 

 session a specimen of this remarkable slug, and 

 thinking that a description of it might interest your 

 readers, I send the following notes. Its chief 

 peculiarity consists in the shell, which is on the 

 hinder part of its back, and not, as in most other 

 slugs, on the head. The length of the shell is about 

 one-third of an inch. From the upper end of the 

 shell two deep furrows traverse the sides of the 

 creature, and terminate at the head. It is of a dingy 

 yellow, deepening here and there into brown. The 

 habits of this slug are curious. It is carnivorous, 

 principally feeding upon worms, of which it is able to 

 swallow specimens longer than itself. It lives most 

 ■of its time under ground, and is therefore difficult to 

 observe. I have arranged mine so that I can at any 

 time remove the top of his subterranean abode and 

 watch liim. He has lived thus for a month, and is 

 in very good condition. — S. 



Water-currents on Gills of the Newt. — In 

 the April number of Science-Gossip Mr. H. E. 

 Forrest asks how the current of water is propelled 

 rapidly along the surface of the gills. The water is 

 carried by the action of vibratile cilia, as may be seen 

 with a good quarter-inch objective, especially when 

 the cilia begin to i-elax their extreme activity. The 

 process is respiratory, the organ of which is the gill, 

 by which the free oxygen of the water is taken up 

 according to the M'ants of the economy. And hence 

 the necessity of a constantly rapid current of the 

 water over the gills. — Q. F. 



METAMORrHOSES OF AMPHIBIANS. — Much in- 

 terest has lately been caused among philosophical 

 zoologists, by certain experiments relating to the 

 metamorphoses of some amphibians. Hitherto it 

 has been regarded as absolutely necessary that this 

 group should be characterized by the intervention of 

 a distinct intermediate stage between the egg and the 

 adult ; although several exceptions occurred, notably 

 that of the Black Salamanders. Dr. Peters has 

 recently made a communication to the Berlin Academy 

 of Sciences, giving an outline of various cases in 

 which no metamorphosis takes place, but where a 

 young frog is developed directly from the egg, without 

 any intervention of the " tadpole " stage. The paper 

 was based upon the researches of various zoologists, 

 chiefly on those of Dr. Bello, who has observed a 

 tree-frog, found at Porto Rico, which lays its eggs 

 far from any water, in which the young breathed air 

 as soon as they were hatched. This frog is Hylodes 

 Martincensis. Dr. Gundlach has succeeded in artifi- 

 cially hatching out some of the eggs of this frog, which 

 were sent to him. In doing so he was enabled to 



watch the entire process in the egg-stage, and he sent 

 Dr. Peters specimens in various stages of develop- 

 ment, who discovered that much of the process of 

 what we call in the amphibians "metamorphoses," 

 in 'this instance occurred within the egg. The tail 

 was gradually reduced before hatching, and had 

 almost disappeared a few hours after birth. The only 

 other instances previously known of absence of 

 metamorphoses (except the Black Salamander), is in 

 the genus Pipa, in which the eggs are hatched in the 

 pits or hollows which cover the back of the mother. 

 In addition to the above a German lady has, perhaps, 

 given to the scientific world, by dint of patience and 

 perseverance, the most remarkable facts. Fraulein 

 Chauvin has succeeded in forcing Axolotis to pass 

 into the other so-called generic form known as Am- 

 blyostoiiia. Some years ago several axolotis did this 

 of their own accord, in one of the Parisian aquaria, and 

 much surprised the world by the act. But no other 

 instance has been given, we believe, and Miss Cliau- 

 vin's is certainly the first where the Ainblyostoma stage 

 has been scientifically brought about by a sudden 

 change of environment. Her plan consisted in gra- 

 dually accustoming the axolotis to a terrestrial 

 existence. A good many died during the process ; 

 but eventually the experiment proved successful, and 

 is scientifically valuable as showing how even new 

 generic types may have been developed through the 

 changed physical geographical conditions produced 

 by the myriads of geological operations which we 

 know have taken place during our planet's past 

 history. 



Singular Star-fish. — In reply to the paragraph 

 headed " Singular Star-fish," in page 94 of this 

 year's SciENCE-Gossir, I beg to inform the writer 

 that in a miscellaneous gathering lately made by a 

 friend in the Bay of Naples I have found numerous 

 small Opliinrida, all of which have six arms. — 

 Major L. 



BOTANY. 



The Fertilization of Mosses. — The moss in- 

 quired about by Mr. Key is a species of the immense 

 genus Fissidens, named F. grandijrons, Bridel, found 

 throughout the Pyrenees, and in the South of France, 

 Baden, and Algeria ; and no doubt, if plants of both 

 sexes were cultivated together, fecundation would 

 take place. With respect to propagation, it must be 

 borne in mind that the moss-spore does not develop 

 into a new individual, but produces on germination a 

 branched confervoid protonema, from certain cells of 

 which young plants are produced. We need not, 

 then, be surprised to find that certain cells of the old 

 plants are capable of development into new indivi- 

 duals, for which in some cases special provision is 

 made, as in the production of gemma; or propagula 

 in Tetraphis pelhicida, Atdacomnium, and others, 



