JENKINS AND Carson, Nervous lmpulse in Worms. 281 
The nerve-cord-muscle preparation can more easily be 
made from Lumbriconereis than from Glycera on account of its 
squirming less. Like Glycera, it is less easily broken than the 
rest of the series worked with. It is less active than Glycera 
but equally irritable; single induction shocks applied to the cord 
20 cm. from the reacting portion produce good contractions. 
The measurements of the cord were taken after killing the prep- 
aration in fresh water. 
EXPERIMENT No. 1, Table XII, postero-anterior, July 24 to 27, 1goOl. 
Length of cord: 21 cm. (114 segments). 
July 24 First four pairs of records, rate: 300 cm. per sec. 
3-9 p- m, Total No. of records (24 pairs), rate: 65 cm. per sec. 
July 25 First four pairs of records, rate: 221 cm. per sec. 
8-11 a.m. Total No. of records (16 pairs), rate: 65 cm. per sec. 
July 25 First three pairs of records, rate: 210 cm. per sec. 
4-6 p. m. Total No. of records (15 pairs), rate: 94 cm. per sec. 
July 26 First three pairs of records rate: 233 cm. per sec. 
ga.m.-5 p.m. Total No. of records (13 pairs), rate: $0 cm. per sec. 
July 27 First pair of records, rate: 42 cm. per sec. 
ga. m. 
The coefficient of variability of the transmission time of the fourteen pairs 
of records that show a rate above 200 cm. per sec, is .37. 
TABLE XD. 
Summary of experiments on Lumbriconerets sp. (a) 
Postero-anterior rate. 
No. of | No. of records | Length of ; 
- aa = = : Rate in cm. 
experiment Distal Erosimal cord in cm. 
I | 14 14 | 21 241 
2 3 | 3 | 9 45 
eee, 4 4 10 45 
Lumbriconereis sp. (b) 
This worm is very abundant in crevices and under rocks 
where it constructs for itself delicate tubular passages by debris 
and gravel cemented together. It is commonly 30 to 40 cm. 
in length and from 5 to 7 mm. in diameter, but owing to its 
great fragility generally only portions of the worm could be se- 
cured for the preparation. The worm is rather inactive, so 
anesthetics were not necessary. Despite its sluggish habits it 
responds to single shocks almost as readily as Glycera, but the 
