252 



SCIENCE-GOSSIP. 



as is the case in most plant cells ; but it may be 

 absent, which is the case with most animal cells. 

 Originally it is never present." 



The composition of the cell consists of two parts : 

 the inner part which is termed the nucleus, the 

 centre of vitality — on this the cell depends for 

 segmentation and aggregation— and the outer or 

 surrounding elementary matter, the cell slime or 

 protoplasma, a compound of carbon and nitrogen, 

 which is of efficiency on that period arriving when 

 the potentiality of the nucleus begins to assert 

 itself, for the segmentation and consequent 

 aggregation of the cellular life, which ultimately 

 reasserts itself in the adult individual. The shape 

 of the nucleus is varied : it is sometimes round and 

 sometimes it is oval, even at times assuming the 

 form of a spheroid. In consistency it is similar to 

 the surrounding elementary protoplasma, generally 

 slightly more solid, never softer than the cell slime, 

 which remains throughout its existence in the 

 same state of density. The core and the protoplasma 

 are the two essentials of all existence. All other 

 particles of matter are subservient to these two 

 great elements or constituting factors of the cell. 

 They must be regarded as passive, that is to say, 

 in a state of quiescence, having been assumed from 

 without in the active bearing of the protoplasm, or 

 formed by the interchange of movement through 

 which this great and beautifully constituted attribute 

 of life is continually passing. Life, or vitality, 

 therefore depends on the growth and development 

 of this original animal cell or ovum. 



Now this term "life," or vitality, which forms one 

 of the attributes, undoubtedly the greatest and 

 grandest attribute of the development of cell struc- 

 ture, is a feature to define which correctly and 

 intelligibly, a variety of attempts has been made by 

 the many who have striven towards a solution of 

 the mystery. So far, however, the definitions or 

 explanations which have been given of life have 

 not been sufficiently concise and explicit, to settle 

 that ever-interesting question as to what is to be 

 understood by "life." Hence the term has been 

 utilized to explain the existence of man and ani- 

 mals equally with that of a mucus, or pus, or white 

 blood corpuscle. Yet the life of man cannot be 

 considered similar, inasmuch as many hundreds 

 of such white blood corpuscles, or elementary units 

 of the tissues, might die in the man without affect- 

 ing the life of man, while on the other hand the 

 man might die and still some of the corpuscles 

 remain ( 17 ). We must look on the life of the 

 individual or animal as life in its totality, for their 

 structures are the aggregation of living units 

 arising from cellular evolution. This evolution 

 embraces essentially different phenomena, some 

 being chemical, others mechanical, so that it is 



( 1T ) " Protoplasm : Life Force and Matter." Lionel S. 

 Beale, M.D., F.R.S. (1870). 



imperative to distinguish between the stage of life 

 which may be considered as life in the fullest 

 degree, that is, the ultimate result of cellular 

 evolution, and that life of each elemental unit 

 which goes to constitute the grander and more 

 perfect organism, for it is not a matter of degree 

 but of kind. The phenomenon of life is one of 

 those mysteries which many have attempted to 

 explain, and the origin of which still remains a. 

 secret feature in the scientific world. All that we 

 can be definitely told is that the phenomenon has 

 its origin in a protoplasmic element, the workings 

 of which have to a certain degree baffled the re- 

 searches of those who have sought to explain 

 them. It is an oft-quoted axiom that omne vivum 

 ex vivo — "all life originates from life" — conse- 

 quently, although it is granted that the protoplasmic 

 element is endowed with vitality, a difference of 

 opinion exists, as to the method it adopts in the 

 exercise of its functional power of amplification 

 for the purpose of building up the material being. 



The term "protoplasm" of itself has given rise 

 to no small confusion, on account of the indis- 

 criminate use made of the term by various writers. 

 It has been made to "differentiate substances 

 essentially diverse, to define matter hard and 

 soft, to elucidate solids and liquids, coloured and 

 colourless, opaque and transparent ; it has been 

 used as an explicative of matter granular and 

 destitute of granules, of matter showing structure 

 and structureless, moving and incapable of move- 

 ment, active matter and passive matter, contractile 

 and non-contractile, matter growing and incapable 

 of change, animate and inanimate." ( 18 ) Therefore 

 it has been suggested, that the use of the term be 

 abandoned on account of this indefinite and vague 

 manner in which it has been employed, for thus 

 having been associated with such mistaken views, 

 it has been regarded as more misleading than 

 useful ( 19 ). Yet the term is requisite when speaking 

 about the constituent parts of the cell, and not- 

 withstanding the erroneous views investigators 

 have made it answerable for, it is the only term 

 recognised scientifically and continued in use. In 

 applying the term, there is one stipulation, how- 

 ever, and it must not be forgotten, it is this : the 

 word " protoplasm " is a morphological term, and 

 must not be understood to convey the idea of, or 

 designate, a definite chemical compound. 



The protoplasm of unicellular organisms and of 

 animal cells appears as a viscid substance, colour- 

 less, and incapable of mixing with water, while its 

 weight is greater than that of water. It contains 

 certain granular bodies, chlorophyll spots, and 

 often crystals, nuclei and objects of observation 

 embedded in the colourless and apparently struc- 

 tureless mass. Accordingly, whether there are 



< 18 ) " Protoplasm." (L. S. Beale. London, 1870.) 

 ( 10 ) Flemming : " Zellsutstanz, Kern und Zelltheilung." 

 Leipzig, 1882. 



