318 THE POPULAR SCIENCE MONTHLY. 



I let the water run out of the net into a small glass, so as to be 

 sure that it contains no other animals, and take a glass tube long 

 enough easily to reach the bottom of the mug. The life here is 

 all in a confusion of panic on account of the cramped quarters. I 

 introduce the tube, holding the upper end tightly closed with my 

 forefinger. The air contained within it permits very little water 

 to enter. 



We have now to keep a sharp lookout. When I perceive a 

 butterfly which perhaps has sprung at a bound to the surface and 

 is now gently sinking back, I try to bring the lower end of my tube 

 close to it. My forefinger is then suddenly raised ; a stream of 

 water, stronger as the tube is deeper in, presses out the escap- 

 ing air and draws the animal in with it. My forefinger is then 

 brought down to close the upper end, the tube is drawn out, and 

 the animal in it is transferred to the collecting-glass. This is a 

 simple method of catching such small and delicate animals, but 

 must be well practiced if one would acquire any skill in it. It can 

 not be used successfully in a rough sea, and when that is the con- 

 dition the student must wait till he gets home. But when the 

 animal is secured, it is a real joy to lose one's self in contemplat- 

 ing it with the lens and microscope. The needle-butterflies are 

 a beautiful object. Their cylindrical, glass-clear shell is firm 

 enough to stand a slight pressure. An animal is caught in the 

 prescribed way and put in a compressorium ; a small instrument, 

 a thin glass-plate or cover, is used with a tortuous movement to 

 bring it closer up on the stand, which is also of glass. A drop of 

 water is made to fall on the stand, the creature to be examined 

 is brought up, and the two plates are twisted till both touch the 

 drop. We might crush our specimen with the apparatus ; but we 

 carefully regulate the pressure so that no harm shall come to it 

 while it is held fast in the same place. It struggles, beating with 

 its wings, but all its exertions are in vain ; it can not in the nar- 

 row space overcome the pressure that weighs upon its shell. 



It is a wonderful view we get under the microscope of the fine 

 muscular fibers crossing one another in the wings, now drawing 

 together and now extending out, and we can follow the ramifica- 

 tions of the nerves and the vessels of the circulation. We perceive 

 the motions of the mouth as it opens and shuts, the pharynx-head 

 with the tongue, which is projected and withdrawn, the connec- 

 tions of the intestine ; we see the heart beat, and can follow the 

 current and eddies of water which are produced in the breathing- 

 pores and certain secretory openings by the beating of innumera- 

 ble cilia in their regular way. The animals are hermaphrodite. 

 We can see the eggs and other products in the organs where they 

 are generated and in the channels through which they are ex- 

 pelled. Only a few hours passed before the needle-butterflies and 



