i g8 



SCIENCE- GOSSIP. 



wall of the tower ; in examining the beautiful 

 arrangements by which different currents of water 

 are formed, some to drive food to the rnastax, and 

 others sediment into the lathe-like opening in the 

 centre where the brick is made. The curious little 

 tube-builder Cephalosiphon limnias I found at the 

 Upper Wake Pond. The tube is rather dark in 

 colour and unsymmetrical in shape, but the rotifer 

 is readily identified by the single long antenna- 

 like process which rises slowly and cautiously out 

 of the tube, ascertaining if all is safe, before dis- 

 playing the cilia. 



Rotifer vulgaris, said to be the most common 

 of the rotifers, is little understood. The mystery 

 of its sexes is still unpenetrated. I have seen the 

 young animalcule escape from the abdomen of the 

 mother, darting in a fraction of a second of time 

 through a longitudinal slit, of which I could find 

 no trace afterwards, and immediately start life 

 on its own account. I have watched the dust from 

 a dry gutter or from moss gradually swell when 

 placed in water and wake into life as Philodine 

 or Rotifer ; I have had it under repeated observa- 

 tion for years, and so has everyone who has studied 

 Kotifera, and it seems astounding that a male has 

 never been seen or suspected. 



Rotifer tardus has a remarkable three-toed foot, 

 and at the base of that foot two more spurs, re- 

 sembling those of Furcularia. It is so slow in its 

 movements that fungoid matter seems to take root 

 to its sides. It is not common. I have taken it at 

 the Leg of Mutton Pond. Actinurus neptxmius is 

 one of the largest and most astonishing forms ; it 

 is quite telescopic, and shuts up into a short angular 

 case, from which the head and tail shoot out with 

 quite startling suddenness. This is constantly 

 happening. as it seldom remains in one position 

 for more than a few seconds. When I have come 

 across it I have found it in water thick with sedi- 

 ment. I have taken it in the culvert of the Eiver 

 Brent at Stonebridge Park, and in the Grand 

 Junction Canal near Acton. 



Asplanchna priodonta is a large free-swimming 

 rotifer, whose vascular system and vibratile tags 

 show well. Its method of expelling digested 

 food is considered archaic ; it is simply rejected 

 through the mouth. It preys on large-sized in- 

 fusoria, which are sucked into the stomach. 

 I have noticed the loricated rotifer, Anurea 

 cochlearis, in process of digestion. For this species 

 the Grand Junction Canal at Queen's Park, and 

 the Leg of Glutton Pond, have been among mv 

 most successful hunting-grounds. Furcularia gibba 

 is common round London, and may be found in 

 nearly every pond, but is rarer in the country. It 

 was quite an unfamiliar rotifer to Dr. Hudson, and 

 several observers had named different animalcula 

 by this name. 



There is no difficulty in identifying Furcularia 

 loTigiseta with its extraordinary development of 

 toes. I found it in the pond at Dollis fill on 



some duckweed. It remained alive for hours in a 

 live-box, occasionally resting and giving me an 

 opportunity of drawing it. but generally swimming. 

 and sometimes, by suddenly bringing the long toes 

 together, giving a leap after the manner of 

 Triarthra. I fancied on these occasions that I 

 could hear a sound produced by' the contact of the 

 toes with the cover glass. 



Dr. Hudson and Mr. Gosse considered the 

 Notomata family to be the most interesting group 

 of the Kotifera. Many of the genera are pre- 

 daceous on other rotifers, and show extraordinary 

 signs of fierceness and rage when confined in a 

 live-box or slightly compressed. I have seen 

 Biglena forcipata seize hold of a piece of con- 

 ferva and shake it like a terrier does a rat. The 

 mastax is toothed and capable of being protruded. 

 Similar behaviour may be watched in many of the 

 family. Furcularia, though included in the 

 group, shows none of this fierceness, and the small 

 puppy-like Biglena catelina is, as far as my ob- 

 servations go, and I have seen it frequently, a 

 quiet, mild-tempered animalcule. 



Pterodina patina is very common, but always 

 interesting ; it can be found nearly everywhere. 

 I once dipped hundreds of them, and I remember 

 no more beautiful sight than these seen with a 

 low power and by dark ground illumination. Some 

 were swimming and others had anchored them- 

 selves by the foot to weeds and were busily lashing 

 the water with their cilia. Their bodies flashed 

 and glowed with light, their little red eyes 

 twinkled, the conferva was bright vivid green, 

 while the minute particles of sediment spinning 

 round in the currents of the ciliated wheels shone 

 like stars against the dark background. 



Polgarthra platiptera is one of the group which 

 have flat blades to aid them in swimming ; the use 

 of these appendages causes them to progress in 

 jerks. The blades, when examined with high 

 powers, are found to be serrated. It is not un- 

 common. Colurus deffexus is one of the smallest 

 of the loricated free-swimmers. It is constantly 

 present • everywhere round London ; but farther 

 north it is, I understand, rarer The little pick 

 with which the head is furnished is best seen from 

 the side. A dorsal view, which from the slight 

 breadth in proportion to the height is rare, shows 

 it to be hyaline, and more like a spade in shape. 

 It is used in breaking up decaying confervae. In 

 the pools left by the tide at Guernsey a rotifer was 

 plentiful that I could not distinguish from C. de- 

 Jtexus. In July 1897 I saw two of this genus tied 

 by a ligament which seemed to come from the 

 shoulders of the animalcula ; but they were so 

 restless that it was impossible to say with exact- 

 ness. I have never repeated the observation. 



Jletopidia solidus resembles Colurus in many 

 respects, but has a flat limpet-shaped body ; it is 

 also common and of the same habits. Stephanops 

 lamellaris is easily distinguished by the disc on the 



