The Microscope. 13 



Structure op Haliotis. — Haliotis is commonly known as 

 the ear shell ; in California it is called abalone. The shell is iri- 

 descent red or green and is used extensively in inlaying papier 

 mache. One of the peculiarities of the shell is a series of open- 

 ings which follow the course of the spiral. The structure of the 

 animal itself presents many interesting features which have re- 

 cently been commented upon by H. Wegmann (O.R. 1884, p. 

 1385). These all go to show that in many points the ear shell 

 is similar to the acephalous molluscs like the clam and the 

 oyster. Thus the renal organs are paired, the heart is provided 

 with two auricles and two well developed gills and two rudi- 

 mentary ones are present. The intestine is ciliated internally » 

 the genital system is remarkably simple and lacks the accessory 

 organs so common in the gasteropods. On the question of 

 paired organs in some gasteropods and their obsolescence in oth- 

 ers, the reader will find many important hints in the article 

 "Mollusca" in the Encyclopedia Brittannica, from the pen of 

 Prof. E. Ray Lankester. 



A Point for Investigation. — Some recent researches made 

 by an English chemist, but not yet published, show that the 

 bright blue color of the bloDdof Limulus and of scorpions is due 

 to the presence of copper. This suggests another microchemical 

 research which might be profitably followed. The curious ma- 

 rine worm Balanoglossus gives oft a strong odor of bromine. It 

 would be interesting to ascertain whether this element is present 

 in these worms in larger quantities than in ordinary sea-water. 



A Group to be Studied. — One sadly neglected but interest- 

 ing group of insects is represented everywhere and especiall)' 

 commends itself to microscopists. This is the group known as 

 Thysanura, or in popular terms '" bristle-tails " and "spring- 

 tails." On turning over some board which has been lying for 

 some time on the ground, one will almost invariably find num- 

 bers of minute insects which jump to a considerable distance by 

 means of a forked spring beneath the body. Others of the group 

 may be found in cellars, under decaying leaves or on growing 

 bushes. To collect them from a board all that is necessary is 

 to hold a small vial so that they will jump into it. If the inside 

 of the vial be moistened with alcohol they will not be able to 

 jump out again. In collecting in the woods the dead leaves 



