336 DR. HUDSON. 



Gone ! Yet stay, there is something that looks like a 

 fringed leg on the edge of the drop ; a half-inch reveals the 

 sad truth ; he has dashed through the concave boundary of 

 his prison — smitten ])erliaps. Narcissus-like, with his own 

 image — and has found an airy grave. 



It would be tedious to tell of all the troubles that may yet 

 beset the observer ; let us then imagine the animal to be 

 handsomely captured and tenderly held by the compressorium, 

 with not more than half of his six legs twisted into some ex- 

 travagant attitude. It is true that it Avill often even then, by 

 means of its powerful muscles, jerk itself regularly every two 

 or three seconds, so as to describe a circle round the points 

 at which it is held. Nothing can be more distressing to any 

 one watching it with a half inch or higher power in the hope 

 of understanding its structure. No jiressure short of a fatal 

 one can prevent the motion ; for Pedalion is of so broadly 

 conical a shape that the glass can only grip two spots at 

 once, and those on opposite sides of its body. But rotifers 

 seem to diifer in their tempers almost as much as human 

 beings ; and noAv and then I have lighted on a docile fellow 

 that will lie still to be looked at. Under these circumstances, 

 I think, few things can be seen more wonderful than the 

 muscular system which moves this animated atom. Here 

 are at least forty striated muscles in a creature not 1-lOOth 

 of an inch in length, and those not mere repetitions of one 

 another, as in the muscles of a caterpillar, but with eveiy 

 pair arranged for some special duty. 



Figure 1 gives a dorsal view of Pedalion, and shows the 

 whole of the dorsal limb (m) and the inner pair (w), with 

 portions of the outer pair (o),and of the pseudopodium (p). 

 Each outer limb is elevated by a pair of muscles (b) , and de- 

 pressed by another pair (a) , each one of which bends round 

 the junction of the limb and body, and slants downwards 

 towards the dorsal or ventral mid line to meet there its corre- 

 sponding fellow; in fact, the muscles for dcj^ressing the 

 outer pair of arms (o) make together a complete circuit of the 

 body, meeting in V-shaped fashion on the mid-dorsal and 

 mid-ventral lines, as well as in the limbs themselves. This 

 is also shown in fig. 2, where all the repeated muscles of fig. 

 1 bear the same letters. 



The dorsal limb (m) is depressed by a pair (A), which run 

 along its sides, and then making a sharp turn at right angles, 

 enclasp the whole body, and meet on the mid- ventral surface ; 

 it is raised, I believe, by branches thrown out by the pair 

 (k), as is best seen in fig. 3; but I never could quite satisfy 

 myself of the working of these muscles. 



