May 2, 1913] 



SCIENCE 



667 



ened, they should be set on end on a cool 

 moist surface and enough melted paraffin 

 poured in to form a bottom four or five milli- 

 meters in thickness in each of the bottles. 

 After cooling, each bottle should be filled with 

 melted paraffin and emptied, a process that 

 should be repeated every few minutes until a 

 rather thick coating has formed on the in- 

 eide. The exterior should be treated in a 

 similar way by dipping the bottles into melted 



Eubber stoppers can be fitted to these bot- 

 tles by warming the neck of each and by 

 pressing a stopper, of the proper size, into the 

 opening before the paraffin cools. If rubber 

 stoppers are not available, ordinary bottle- 

 corks, which have been coated with paraffin, 

 can be used with quite as good results. 



Alban Stewart 



Ukiversity op Wisconsin 



notes on cuban fresh-water fishes 

 While collecting fossils in the province of 

 Santa Clara, Cuba, in 1911, my work took me 

 to Baiios de Ciego, Montero, 30 miles north of 

 Cienfuegos. Here occur three hot springs 

 having a temperature, respectively, of 93, 96 

 and 99 degrees Fahrenheit. These springs are 

 grouped close together, not more than 20 

 yards apart and about 200 yards from the 

 Analla Eiver into which they drain. The 

 springs of 93 and 96 degrees temperature are 

 walled in and the latter is surrounded by a 

 hotel. The one of 99 degrees temperature is 

 of largest volume and has direct communica- 

 tion with the river. In this spring as well as 

 in the drainage water of the other springs and 

 the cold water of the river, I found a great 

 many fishes, mostly viviparous. 



The following species have been identified 

 from the spring : 



Syrnbranchus marmoratus Bloch. 



Gambusia puncticulata Poey. 



Glaridichthys falcatus Eigenmann. 



Girardinus matallicus Poey. 



Poecilia vittata Guichenot. 



Seros tetracanthus (Cuv. & Val,). 



Of these the eel-like Syrnbranchus marmo- 

 ratus was found only in the hot spring. The 



other species, so far as I was able to observe, 

 were common to both the cold water of the 

 river and that of the hot springs, becoming 

 acclimated by degrees, until they were finally 

 able to live in the hottest water, 37° Centi- 

 grade, approximately that of blood tempera- 

 ture. 



I was curious to know if it were possible for 

 these fishes to live equally well in the hot 

 spring water of 99 degrees temperature and 

 the river water of 60 degrees temperature 

 without first going through a process of accli- 

 mization, so conducted a number of experi- 

 ments. It was quite evident that fishes could 

 gradually come from the cold water into that 

 of the hottest temperature, so I took a number 

 from the hot spring, carefully catching them 

 in a net so as to avoid injury and placed some 

 in river water and others in water from the 

 other springs. Those placed in water of 93 

 degrees temperature seemed to live in it aa 

 well as in that of 99 degrees, but th'-se placed 

 in river wat€r, out of eleven fishes, nine died 

 within ten minutes. The other two lived. 



This experiment was repeated several times 

 with similar results; more than two thirds 

 failing to resist the sudden change of tem- 

 perature. 



I am unable to tell whether those used in 

 the experiments were Gamhusia puncticulata, 

 Glaridichthys falcatus, Girardinus metallicus 

 or Pcecilia vittata, but probably they were 

 mostly the latter genus and species, as this 

 form was most abundant in the Chapapote 

 spring. 



While living in the hotel during a heavy 

 storm the Analla Eiver overflowed, sending a 

 branch across this Chapapote spring. The 

 following day we pumped out the water, find- 

 ing a great many viviparous fishes, probably 

 all of the four determined small species and a 

 number of viajecos, Heros tetracanthus. Evi- 

 dently they had all become acclimated to the 

 hot water during the time of this overflow. 



Besides the species mentioned, the collection 

 contains two species which were not found in 

 the warm spring, Gamhusia punctata Poey, of 

 which two were obtained from the Eio Analla 

 and several from a tributary of the Zaza, and 



