Table 1.

Responses to moderate pressure delivered to a mid-body segment in leeches at different developmental stages

Stage	Number of intact leeches that produced CI in control solution	Number of intact leeches that produced CI in BMI solution	Number of dissected body wall preparations that produced CI in BMI	Total
52-55% ED	10 of 10	10 of 10	3 of 3	13 of 13
60-70% ED	0 of 8a	5 of 8	2 of 3	7 of 11
> 100% ED	0 of 5a	5 of 5b	5 of 5b	10 of 10

^a Animals older than 60% ED produced LB in response to touch when tested in saline solution.

^b These leeches were nearly intact, but a small incision was made at the anterior end to facilitate drug access to the ventral nerve cord.