BIOLOGY, MARINE — MAYER. Ill 



by anyone at the laboratory, although one investigator suffered in 

 this respect in Tampa or Key West before arriving at the labora- 

 tory. We have to contend with the fact that investigators come to 

 the laboratory much depleted, physically, from the excessive labor 

 and confinement of their college duties, and it is essential that condi- 

 tions at Tortugas should preclude the possibility of the contraction of 

 any tropical diseases. Fortunately there are no breeding-places for 

 mosquitoes on Loggerhead Key, although Culex is occasionally 

 blown upon the island from the Florida Keys, 40 miles distant. 



North of the dock and opposite the kitchen, a well-ventilated, 

 cool, aquarium-laboratory was constructed. This has a floor space 

 of 20 by 20 feet, and contains two tanks, a pump for salt water, and 

 other conveniences for maintaining marine animals in conditions 

 approaching those of nature. A cool. well-ventilated aquarium, with 

 facilities for altering the intensity of light, is indispensable to a labor- 

 atory affording unrivaled facilities for physiological and embryolog- 

 ical studies. The ocean-water at Tortugas is warmer than that of the 

 aquarium ; hence animals may be maintained at their normal tem- 

 perature. This advantage will be appreciated by all who have been 

 discouraged by the unavoidably high temperature of small aquaria 

 in northern laboratories. Suffice it to say one may maintain medusae, 

 worms, Crustacea, etc., in excellent health at Tortugas, in aquaria, 

 for months. 



A considerable quantity of fresh water is necessary in a region 

 where it may not rain for a month at a time, and where wells can 

 not be made. Accordingly two galvanized-iron cisterns capable of 

 holding 1,326 cubic feet of water were installed, and also a wind-mill 

 and salt-water tank to economize the use of fresh water, and to 

 supply the laboratory and water closets. 



Laboratory tables for microscopic work must be independent of 

 the building so as to avoid the communication of vibrations one to the 

 other. This was accomplished by driving the legs of the tables 

 firmly into the ground through holes in the floor, and not permitting 

 them to touch the building at any point. The eight tables in the main 

 laboratory building are L-shaped, one arm of the L being at the right 

 hand of the investigator and the other facing the northern light. 



The original composition material used for roofing the laboratory 

 buildings began to deteriorate in the hot, moist climate and to develop 

 leaks. The buildings were therefore covered with heavy canvas, 

 painted. This does not interfere with the portable character of the 

 buildings, and while expensive, gives a cool, efficient roofing capable 



