SCIENCE-GOSSIP. 



321 



te re pr.-.-rlasm in pafs^n^ through the various 

 changes necessary to consummate the purpose of 

 its creation — the evolution of the cell and ultimately 

 the adult form ; the results consequent on such 

 evolution or development originating from the 

 continuity of the segmentation of the single adult 

 cell. Now, the protoplasmic mass influenced by 

 the gradual changes introduced by evolutionary 

 progression, and ceasing to remain protoplasm, 

 must, in the ordinary course of nature, be by 

 some method renovated. That is, the elemen- 

 tary parts or atoms so absorbed or abstracted 

 in this progressive feature of nature must 

 be replaced. Consequently nature arranges for 

 this compulsory absorption, which is continually 

 active, by enabling all bodies to assimilate new 

 matter to make up the material which has been 

 utilized for what may be termed the higher 

 purposes. The formation of centres of new living 

 matter must not be conceived as being derived or 

 originating from the aggregation of minute particles 

 brought from distant parts of the organism. 

 Because, should this be correct, only one interpre- 

 tation of the phenomenon — and that an incorrect 

 one — could be offered, viz. : that these minute 

 particles had been existing in such distant localities, 

 and had previously passed through, in their move- 

 ments, animated parts, to enable them to arrive at 

 the point or nucleus which became the centre of 

 living matter. The movement of matter has been 

 fully discussed, and the movement of renovating 

 material is regarded as not being from distant 

 parts to a centre, but in the opposite ratio — from 

 the centre of living matter to the more distant 

 surroundings. Moreover, by the investigation of 

 these movements of living particles, it is estimated 

 that "only matter passing towards the centre is 

 dissolved non-living pabulum, and that if living 

 particles were suspended in this, they would be 

 filtered off by the formed material, and would 

 ne-. er reach the living matter " ('■). This apparently 

 means to convey the idea, or rather fact, that in 

 a process of the natural attraction of non-living 

 pabulum, containing proteids or other elements 

 imbued with life, towards the centre of assimila- 

 uch living particles or proteids would by 

 attraction be absorbed by the living mass 

 through which in the natural progress to the living 



rot ^..le. p. H4. 



■ ;i* and Mode 

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■ 



■ trans- 



-'.hunnen uber 

 Klruclur und d'-rn Wacb- 



I General Anatomy 



. *-arrd In the 



trtchlo- 



■ 



centre it — the pabulum — would, by the law of 

 attraction have to pass, that is to say, in one 

 direction only, towards and not from the centres 

 of living matter. 



In providing for the renewal of matter abstracted 

 in the consummation of the protoplasmic mass, 

 we have somewhat anticipated the progressive 

 evolution of the cell. During the progressive 

 formation of the cell contents, a development 

 which assumes the form of a small central point 

 or pip is introduced by some unknown cause or 

 causes. This is as important in the economy of 

 cell life as is the presence of protoplasm. This 

 feature of cell evolution had, previous to 1S33, 

 escaped the attention of observers ( 6 ). Its import- 

 ance in the economy of development was soon 

 made manifest ("), though notwithstanding the 

 value of this body it remained neglected as the 

 interesting vital phenomenon of protoplasm became 

 known ("). It has now been demonstrated that 

 this part is of quite as great importance to the 

 elementary body as is the protoplasm. This 

 body found within the cell is the nucleus. It 

 was regarded as being a small vesicle; indeed, 

 it was considered a structural formative vesicle 

 containing a smaller nucleus ; in other words, a 

 small cell within a larger cell. In like manner (•') as 

 it came to be recognized that protoplasm was the 

 vital substance of the cell, so it was discovered that 

 the form of the nucleus was of minor importance. 

 Its vitality depends far more upon the presence in 

 it of certain substances, the arrangement of which 

 may vary very considerably according to the con- 

 dition of the nucleus, whether it is in an active or 

 quiescent condition, than upon its shape. Richard 

 Hertwig ( Ul ) prefaces his remarks by the following 

 sentence: "It is necessary to state at the com- 

 mencement of my observations, as the most 

 important point to be considered in classifying the 

 various nuclear forms, that they all possess a certain 

 uniformity in composition. Whether the nuclei of 

 animals or plants, or Protista, be under examina- 

 tion, it is invariably seen that they are composed 

 of a larger or smaller quantity of a material which 

 I shall call nuclein substance — nuclein." The 

 nucleus is not now considered as a vesicle in a cell, 

 the idea of Schwann and Schleiden, but is defined 

 as a "portion of a special substance which is distinct 

 )i in Die frotoplasm, and to a certain extent separate 

 from it, and which may vary considerably as to form, 

 both in the resting and actively dividing ft udithn " ("). 



i'fo b§ continued.) 



Verteukate I'ACNa oh Siiuoi'Siiire.— The 



Carador: and Severn Valley Field Club is appealing 



for assistance in compiling notes upon tin: verte 



1 animals of the county, which it la Intended 



:.li»h as soon as sufficiently complete. Lists 



n'l dell 



detailed particular! may be obtained from 

 M, 11 1 Forrest, 17, Castle Street, Sim . i"-, 



