The problem of age, growth, and death; a study of cytomorphosis, based on lectures at the Lowell Institute, March 1907 . us to speak in general terms inregard to the growth of cells, and renders it superflu-ous to stop and discuss for each part of the bodythe size of the cells which compose it, or to seek toestablish different principles for different animalsbecause their cells are not alike in size. Now we pass to a totally different aspect of celldevelopment, that which is concerned with the degen-eration of cells. For we find that, after the differ-entiation has been accomplished, there is
The problem of age, growth, and death; a study of cytomorphosis, based on lectures at the Lowell Institute, March 1907 . us to speak in general terms inregard to the growth of cells, and renders it superflu-ous to stop and discuss for each part of the bodythe size of the cells which compose it, or to seek toestablish different principles for different animalsbecause their cells are not alike in size. Now we pass to a totally different aspect of celldevelopment, that which is concerned with the degen-eration of cells. For we find that, after the differ-entiation has been accomplished, there is a tendency Irving Hardesty, Observations on the Medulla Spinalis of the Elephant,with Some Comparative Studies of the Intumescentia Cervicalis and theNeurones of the Columna Anterior, Journ. Co77ip. Neurol., xii, 125-182,pis. ix-xiii. 68 AGE, GROWTH, AND DEATH to carry the change yet further and to make it sogreat that it goes beyond perfection of structure, sofar that the deterioration of the cell comes as a con-sequence. Such cases of differentiation we speak ofas a degeneration, and it may occur in a very great. Fig. 23. Group of Five Nerve CellsFROM THE First Cervical Ganglion of aChild at Birth. Specimen preserved withosmic acid. X 500 diams.—After C. number of ways. Very frequently it comes aboutthat the alteration in the structure of the cell goes sofar in adapting it to a special function that it is un-able to maintain itself in good physiological condition,and failing to keep up its own nourishment it under-goes a gradual shrinkage which we call atrophy. Avery good illustration of this, and a most important THE CELLULAR CHANGES OF AGE 69 one, is offered us by the changes which go on in thenerve cells in extreme old age. This is beautifullyillustrated by the two pictures which are now before
Size: 1418px × 1762px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectde, booksubjectoldage
