64 



SCIENCE 



LN. S. Vol. XXV. No. 628 



in captivity and exhibited one of the charac- 

 teristic egg-rafts and a photograph of another. 

 During September, 1906, three fishes that had 

 been under his observation in the aquarium 

 at Woods Hole for some time spawned. The 

 rafts were quite transparent, somewhat elastic, 

 and non-adhesive, and floated at or near the 

 surface in a partly collapsed condition; they 

 were from 45 to over 90 cm. long, about 7.5 

 cm. wide and about 6 mm. thick, with ab- 

 ruptly tapering ends; the eggs are .6 mm. in 

 diameter and exceedingly numerous, thickly 

 infiltrating the jelly. One fish that produced 

 a band of eggs 45 cm. long on September 24 

 laid another string 92 cm. long on October 8. 

 The consecutive ripening of the ovaries is 

 doubtless normal, but there is at least one 

 observation (at Woods Hole, several years 

 ago) of the simultaneous discharge of two 

 egg-bands. In none of the cases where these 

 fishes have spawned in captivity have the eggs 

 been fertilized, and the embryology remains 

 unknown. 



The second paper was by Dr. M. W. Lyon, 

 Jr., on ' Local Races of Bornean Squirrels.' 

 He exhibited eight different forms of squirrels 

 of the Sciurus prevostii group found in north- 

 ern and western Borneo, pointing out their 

 characters and showing how the extreme forms 

 were connected by forms possessing interme- 

 diate characters. Material at the present time 

 is not sufficient to show complete specific in- 

 tergradation. A large river proved a very 

 effectual barrier in separating two very dis- 

 tinct races. In the discussion which followed. 

 Dr. Hitchcock asked if two or more of the 

 exhibited races coexisted in the same locality. 

 Dr. Lyon replied that such was not known 

 to be the case, and that as a rule among mam- 

 mals when two species of the same genus in- 

 habit the same area, they usually belong to 

 very difl^erent groups in that genus or to dif- 

 ferent subgenera. He thought that the squir- 

 rels under discussion should form a distinct 

 subgeneric group. Dr. Gill deplored the 

 increasing number of genera and subgenera 

 based on slight characters. Dr. Stiles re- 

 marked that in some groups of animals a good 

 criterion for establishing genera had been 

 found when two forms possess a character not 



found in a third form; two distinct genera 

 are then present, but the author he referred to 

 makes no use of subgenera in this scheme. 

 Dr. Stejneger said that whether definite 

 natural groups were called genera, subgenera 

 or comprehensive species was merely a matter 

 of definition of terms, the facts expressed re- 

 mained the same. Dr. Lyon thought the 

 multiplication of genera and species was de- 

 plored by the non-specialist but was of much 

 assistance to the specialist in any large group 

 of organisms. 



The third paper was read by Mr. Karl F. 

 Kellerman, on ' The Use of Copper in Sanita- 

 tion.' It is evident that a scourge of polluting 

 algae is an emergency condition. The employ- 

 ment of copper sulphate to eradicate this pol- 

 lution is satisfactory both from the theoretical 

 and the practical standpoint. Similarly, cop- 

 per treatment of unfiltered supplies for the 

 purpose of controlling or stamping out water- 

 borne diseases should be considered an emer- 

 gency contingency and should never be more 

 than a temporary expedient which local condi- 

 tions might make necessary until permanent 

 means of purifying the water could be estab- 

 lished. The question of sterilizing or disin- 

 fecting a water supply even two or three years 

 ago was looked upon with great disfavor, but 

 is now recognized by sanitary engineers to be 

 necessary or at least desirable in some cases. 



Many chemicals have been proposed to effect 

 sterilization of this character, among which, 

 besides copper, may be mentioned electrolytic 

 chlorine, ozone, lime, silver chloride and vari- 

 ous specially named trade products. The selec- 

 tion of the most suitable chemical and the 

 method of applying this chemical for con- 

 tinuous disinfection of a water supply are 

 problems for the future. Such treatment 

 probably will be carried on in connection with 

 filtration, both because of the greater oppor- 

 tunity for removing the chemical employed 

 and because of the necessity of keeping the 

 water free from sediment and similar im- 

 purities. 



As with the algse, the different species of 

 bacteria vary in their sensitiveness to copper. 

 Many of the saprophytic bacteria usually 

 present in water are highly resistant, some. 



