ANIMAL-PLANTS AND PLANT-ANIMALS. 687 



region, the nights in the tropics are made light by a curious, brilliant 

 phenomenon : particularly bright sparks flash out in the ocean, at 

 places where the waves break over rocky cliffs. Over one hundred kinds 

 of animals may co-operate in producing this magic effect. Among 

 these are the Salpce, the life-history of which Chamisso learned on his 

 voyage around the world. He was the first to prove that the Salpm 

 which cling together in chains do not vary at all from those swimming 

 about singly. Other agents of a phosphorescent sea are the Medusa; 

 (sea-nettles) — many-colored animals, possessing the most weird of 

 forms. Some kinds have the shape of a bell ; long filaments hang 

 down from the edge, and in the center they have long arms to capture 

 and paralyze their prey ; in this they are aided by a number of those 

 nettle-like organs mentioned in connection with the polyps. 



Occasionally these queer creatures become visible on the surface, 

 in masses several miles in extent. The material of which the body is 

 composed seems to be chiefly water, as a medusa, about twenty pounds 

 in weight, yielded when dried only thirty grammes of gelatinous flakes. 



After the ominous sea-serpent, one of the most interesting of the 

 beings which inhabit the mysterious depths of the ocean is Huxley's 

 Uathybius, made of nothing but shapeless, motionless slime. It has 

 been supposed to be the common origin of the animal and the vege- 

 table kingdom, from which all beings have gradually been developed. 

 But lately science has become doubtful as to its true properties, and 

 has begun to question its organic nature ; many natm-alists consider it 

 nothing more than gelatinous gypsum. Another animal, somewhat of 

 this nature, which several years ago crossed the path of science, like a 

 flickering will-o'-the-wisp, is the Eozo'on Canadensis ; gradually it has 

 become more and more deprived of the animal characteristics once 

 ascribed to it, and has been again assigned to the inorganic world. 



Many are the errors and pitfalls that mark the path along which 

 ever-searching Science strives onward to truth ; and yet even these, in 

 their way, show a triumph gained by the divine power of the human 

 mind over its human failings ! — {Abstracted from Virchow and Holtz- 

 endorffer's " Sammlung gemeinverstandlicher wissenschaftllcher Vbr- 

 trdge") 



Professor Edward S. Holden has sketched in "The Overland Monthly" a 

 plan for co-operative photography of the stars. Under ordinarily existing con- 

 ditions of doing the work, it would take an observatory one hundred and forty 

 years to make a complete photography of the heavens, or ten observatories four- 

 teen years. The desirability of several observatories engaging in the work 

 together is therefore obvious. Photography may be expected to help in the dis- 

 covery of new asteroids ; in the search for the hypothetical planet beyond Nep- 

 tune ; in making star-maps ; in finding stars that make no impression on the eye 

 or telescope ; in accurately fixing the aspect of the sky, as it is for the benefit of 

 students in all the future and for comparative astronomy; and for many other 

 purposes of practical and scientific importance. 



