294 



Marvels of the Universe 



pieces the worms and other soft-bodied animal organisms upon which the King Crab feeds ; and in 

 front of the mouth there is a pair of nipper-shaped jaws used for pushing food into the mouth. 

 The part of the body beliind the waist-like joint is produced sideways into a shelf-like ridge armed 

 with spines, and it is hollowed out beneath to form a chamber for six broad foliaceous appendages, 

 the last five of which carry two clusters of delicate plate-like gills. Loosely, but strongly-jointed 

 to the end of the body, there is a long, spiniform tail. 



From this description it will be seen that, e.Kcept for the fusion of all the segments of the body 

 to form the two areas above described, the Iving Crabs have a strong resemblance to those very 

 ancient creatures called Trilobites, which occur in the earliest fossiliferous rocks, but became e.xtinct 

 no one knows how many millions of years ago. Like the Trilobites, too, they have a pair of large 

 kidney-shaped eyes, each composed of multitudes of ocelli, on the upper side of the body. 



King Crabs are essentially shallow-water species, usually living on sandy or muddy bottoms 

 at a depth of not more than six fathoms. In the early sununer they come to the shore in great 

 numbers to spawn ; and advancing with the spring-tides they leave their eggs in the mud near 

 high-water mark so that they are exposed to the heat of the sun between the high tides. 



Existing King Crabs, of which there are several well-marked species, have a curious distribution. 

 They are found only on the western coast of the Atlantic, where they range from about the latitude 

 of New York to the Gulf of Mexico, and on the western shores of the Pacific, from Japan in the 

 north to Borneo and the adjacent islands in the south. That they formerly lived in European 

 waters is shown by the occurrence of fossil species both in Tertiary deposits and in the chalk and 

 other rocks of the Secondarv" epoch : and their wide geographical separation at the present time seems 

 to be only intelligible on the supposition that there were formerly, although not necessarily 



contemporaneously, shallow water coast-lines 

 between Europe and North America on the one 

 hand and between Europe and Eastern Asia on 

 the other, and this shows what far-reaching 

 inferences as to the past history of the earth 

 may be drawn from the study of one single small 

 group of animals. 



A LIVING SKELETON LEAF 



BY EDW.ARD STEP, F.L.S. 



nolo ()»] 



Th. 



the nerves. E 

 taken for one 

 the grass. 



LATTICE 



light portions of the It 



t for its colour ai 

 of the leal-skelet 



[ir, J'lomer Yoii.ng, 

 LEAF. 



af are clear spaces between 

 id freshness it might be mis- 

 jns found in -winter among 



It is a noticeable peculiarity of manj' water- 

 plants that grow with their leaves submerged 

 that the latter are thin and slender as a whole, or 

 are divided up into a number of thread-like parts. 

 A familiar instance is afforded by the common 

 Water-Crowfoot of our ponds and ditches, which 

 has leaves of two sorts, neither having the 

 slightest resemblance to the other. The one kind 

 of leaf is more or less ivy-shaped, feeling greasy 

 to the touch and persistently floating on the 

 surface of the water ; the other kind is spht up 

 into a large number of dark green threads, and 

 is always spread out at some distance below the 

 surface. The floating leaf acts as a buoy, enabling 

 the flowers to rise into the air. The submerged 

 leaf is so greatly divided in order to expose as 

 great a surface as possible to the water, and so 



