< ave 

 Chance 



SCIENTIFIC SIDE-LIGHTS 



90 



are a modern example of rude tribes thus 

 given to dwelling in caves in the rocks. But 

 caverns are so convenient that they are now 

 and then still used in the civilized world, 

 and most of us have seen some cave in a 

 cliff forming the back of a fisherman's cot- 

 tage, or at least a storehouse. TYLOR An- 

 thropology, ch. 10, p. 229. (A., 1899.) 



444. CEDARS OF THE HIMALAYAS 



Timber for the Gods. On the Himalayas 

 the acicular-leaved form of trees is distin- 

 guished by the mighty thickness and height 

 of the stem as well as by the length of the 

 leaf. The chief ornament of the mountain 

 range is the cedar Deodwara [deodar] (Pinus 

 Deodara, Roxb.) [Cedrus Deodara], which 

 word is, in Sanskrit, dewa-daru i. e., tim- 

 ber for the gods its stem being nearly from 

 13 to 14 feet in diameter. It ascends in 

 Nepaul to more than 11,700 feet above the 

 level of the sea. More than 2,000 years ago 

 the Deodwara cedar, near the River Behut 

 that is, the Hydaspes furnished the timber 

 for the fleet of Nearchus. HUMBOLDT Views 

 of Nature, p. 317. (Bell, 1896.) 



445. CELL, THE FUNDAMENTAL 

 UNIT OF ALL LIVING THINGS The first 

 of the great fundamental conceptions re- 

 ferred to is the cell theory, which was defi- 

 nitely established for plants in 1838, and 

 immediately afterward for animal struc- 

 tures. The theory is that all the parts and 

 tissues of plants and animals are built up 

 of cells, modified in form and function in an 

 infinite variety of ways, but to be traced in 

 the early stages of growth, alike of bone and 

 muscle, nerve and blood-vessel, skin and 

 hair, root, wood, and flower. And, further, 

 that all organisms originate in simple cells, 

 which are almost identical in form and 

 structure, and which thus constitute the 

 fundamental unit of all living things. 

 WALLACE The Wonderful Century, ch. 14, p. 

 143. (D. M. & Co., 1899.) 



446. 



The Constitution of 



the Ameba. The creature which natural- 

 ists call the Ameba, one of the lowest in the 

 animal series, consists of nothing but an 

 apparently simple and formless jelly. But 

 simple, and formless as it appears to be, this 

 jelly exhibits all the wonder and mystery of 

 that power which we know as life. It is in 

 virtue of that power that the dead or inor- 

 ganic elements of which it is composed are 

 held together in a special and delicate com- 

 bination, which no other power can preserve 

 in union, and which begins to dissolve the 

 moment that power departs. And as in vir- 

 tue of this power the constituent elements 

 are held in a peculiar relation to each other, 

 so in virtue of the same power does the com- 

 bination possess peculiar relations with ex- 

 ternal things. It has the faculty of appro- 

 priating foreign substances into its own, 

 making them subservient to the renewal of 

 its own material, to the maintenance of its 

 own energy, and to the preservation of its 



own separate individuality. It has the 

 faculty, moreover, of giving off parts of it- 

 self, endowed with the same properties, to 

 lead a separate existence. This same sub- 

 stance, which when analyzed has always the 

 same chemical composition, and when alive 

 has always the same fundamental proper- 

 ties, is at the root of every organism, 

 whether animal or vegetable. ARGYLL 

 Unity of Nature, ch. 2, p. 29. (Burt.) 



447. CELLS THE POPULATION OF 

 THE VITAL KINGDOM Perfect Division of 

 Labor Definition and Size of Cell. What, 

 then, is a cell ? Imagine a speck of this liv- 

 ing matter, averaging, say, the one- four- 

 hundredth of an inch in diameter, of 

 rounded shape, bounded by a kind of en- 

 velope, and having a particle (the nucleus) 

 somewhere or other embedded in its inte- 

 rior, and you will have a fair conception of 

 what a cell of ordinary size and form is 

 likely to be. Some cells we know of nerve- 

 cells, indeed average only the one-five- 

 thousandth of an inch, or less, in diameter; 

 and between big cells and little cells there 

 are, of course, all gradations in size. These 

 cells, then, are the workers of the body. 

 They are the population of the vital king- 

 dom. . . . There is perfect division of 

 labor in the living state. One group of cells 

 does not interfere with the work of another 

 group. Each piece of labor, from the build- 

 ing of bone to the making of gastric juice, 

 is carried out independently and thoroughly 

 by workers set apart for the given purpose. 

 The economy of a bee's hive is not more 

 rigidly ordered than is the work of our own 

 body in respect of its laborers and their 

 specific duties. ANDREW WILSON Glimpses 

 of Nature, ch. 25, p. 81. (Hum., 1892.) 



448. CERTAINTY AND CONJECTURE 



True Science Will Not Confuse. The 

 burden, however, of this celebrated lecture 

 [of Virchow] is a warning that a marked 

 distinction ought to be made between that 

 which is experimentally proved and that 

 which is still in the region of speculation. 

 . . . He insists that it [speculation] 

 ought not to be put on the same evidential 

 level as the former. " It ought," as he 

 poetically expresses it, "to be written in 

 small letters under the text." The audience 

 ought to be warned that the speculative 

 matter is only possible not actual truth 

 that it belongs to the region of "belief," 

 and not to that of demonstration. As long 

 as a problem continues in this speculative 

 stage it would be mischievous, he considers, 

 to teach it in our schools. " We ought not," 

 he urges, " to represent our conjecture as a 

 certainty, nor our hypothesis as a doctrine: 

 this is inadmissible." TYNDALL Fragments 

 of Science, vol. ii, ch. 15, p. 397. (A., 1900.) 



449. CERTAINTY OF INSTINCT 



Young Turtles and Crocodiles Readily 

 Find Their Way to Unseen Water. Dr. 



