234 
Psyche 
[September 
(1968) describing the trail-laying behavior of Crematogaster perin- 
gueyi. This work has independently established the existence of tarsal 
trail-laying in Crematogaster . In the present article, I report the 
same form of trail-laying in a second species of Crematogaster and 
identify for the first time the location of the gland reservoir and 
discuss some of the physical and chemical properties of the pheromone. 
MATERIALS AND METHODS 
C. ctshmeadi is an arboreal ant, dwelling in dead hollow branches 
and in all kind of cavities in dead wood. Its range is the coastline 
from Virginia to Florida and the Eastern Gulf States (Creighton 
1950). In my field studies on the Florida Keys the existence of 
efficient scent trails in C. ash?neadi has been verified by means of 
traditional experiments. 
Our laboratory colonies, collected from red mangrove trees 
(Rhizophora mangle), were established in horizontally piled pieces 
of hollow mangrove branches, on wooden frames of 20 X 25 cm, 
kept in plastic trays of 30 X 45 X 17 cm 1 in size with the inside 
walls coated with talcum powder to prevent escape. A horizontal 
cylindrical wooden bridge, 3 cm in diameter and 50 cm in length, 
connected the nest area with the feeding station where the ants 
were offered water, honey and shrimp. The colonies were kept at 
regular room temperature. To begin trail-laying experiments a 
colony was first starved for 5 days, then a movable side bridge of 
24 cm in length was added to the old pathway between the nest and 
feeding station. By maneuvering this side connection we were able 
to offer a scouting ant a new honey source and control the passages 
of newcomers. Movements were analysed by slow motion cinema- 
tography (16 mm film, 64 frames per second). 
Localization of an active source of the trail in the ant body was 
accomplished by extracting fractionated body parts in petroleum ether. 
Collected batches of identical body parts of 20 ants were crushed 
Fig. 1. — Schematic of bridge structure used in trail assays. 
