Harper's New Monthly Magazine Volume 104 December 1901 to May 1902 . hens egg, but theminute and delicate little surface-float-ing egg of some sea-urchin) normally di-vides into two, four, eight, and ad, infi-nitum cells to form the adult, what willhappen if you shake these cells apart ? The general answer to all these ques-tions is that the unexpected will rarely acts according to the reason-ing of the closet philosopher. Out of thecareful observation of the unexpected,however, is coming the rationale of thelife processes. But the initial step is tostudy the undisturbed process of
Harper's New Monthly Magazine Volume 104 December 1901 to May 1902 . hens egg, but theminute and delicate little surface-float-ing egg of some sea-urchin) normally di-vides into two, four, eight, and ad, infi-nitum cells to form the adult, what willhappen if you shake these cells apart ? The general answer to all these ques-tions is that the unexpected will rarely acts according to the reason-ing of the closet philosopher. Out of thecareful observation of the unexpected,however, is coming the rationale of thelife processes. But the initial step is tostudy the undisturbed process of divisionthrough cell lineage. The transformation of the simple fer-tilized egg cell is always accomplished bysplitting up into many cells, which ulti-mately constitute the various tissues. Itis obviously a matter of great interestand importance to trace the lineage ofthe tissues backward towards the undi-vided egg. This has been done to suchan extent that we can designate the par-ticular cells that give rise to the outercovering of the body, to the nerves, to the. Interior of the Biological Laboratory Twin Union of two Individuals of Samia Cecropia alimentary canal, and to the reproduc-tive and germ cells. Very early in thehistory of the embryo the future func-tional and structural regions are markedoif, and there is a beginning of whatSpencer termed the physiological divisionof labor. Some biologists are inclinedto carry this back still further, into thecomponents of the egg itself. One would suppose that any rude dis-turbance of this beautiful process wouldabruptly terminate life. Quite the con-trary, for again the unexpected number of amusing and at the sametime highly instructive experiments havebeen made by shaking apart the cellsafter the egg has broken up into fouror even into eight. The remarkable gen-eral result has been obtained that theseisolated cells do not die, but again sub-divide and form a lot of twin or quad-ruplet individuals, as the case may
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