HAVING had living lampreys of various ages under observation in the biological laboratory of Johns Hopkins University, I present the following facts as to the ability of these animals to live in a very limited space. I received, about the middle of May, from Ithaca, N. Y., two lots of lamprey eggs, about six dozen eggs in each lot. They were shipped by express and must have been on the road about twenty to twenty-four hours. They had been shoveled out of the "nest," with about 2 1. of gravel, and put into two tin buckets of 8 1. capacity. The space in the buckets above the gravel was filled'with water, and in one of the buckets were some three dozen larval lampreys ranging from 2 cm. to 12 cm. in length. None of these eggs developed, although they were put into running water as soon as they reached the laboratory. My experience with the small larvae (about 5 mm. in length) was more successful. I obtained one hundred or more of these from a stream at Ithaca, and brought them to Baltimore in two glass jars of 3-4 1. capacity each. A small quantity of gravel was placed in the bottom of each jar for the larvae to bury themselves in, and the water was kept cool by partially emptying the jars from time to time, and refilling them with ice water from the coolers on the train. The journey lasted for about eighteen hours, and all the larvae, except three or four, reached the laboratory in good condition. The small amount of sediment in the city water proving disastrous to the welfare of the larvae, clear spring water was obtained every few days, and this was kept cool by allowing the jars to stand in larger vessels of running water. Even with this arrangement the deaths averaged one per day, and about the first of August the remaining larvae were killed and