Journal of morphology . The multicellular Microstoma behaves essentiallyin the same way as the unicellular Stentor, or the multinucleateOpalinopsis of Sepia. The Microstoma organization duplicatesitself, and fission follows. The chain of buds thus formedbears a most striking resemblance to that of Opalinopsis, andthe resemblance must lie deeper in the organization than cell-boundaries. Compare the results obtained by artificial division in twosuch forms as Stentor and Hydra. The two courses of regen- 650 WHITMAN. [Vol. VIII. eration are so exactly parallel that one cannot fail to see atonce th
Journal of morphology . The multicellular Microstoma behaves essentiallyin the same way as the unicellular Stentor, or the multinucleateOpalinopsis of Sepia. The Microstoma organization duplicatesitself, and fission follows. The chain of buds thus formedbears a most striking resemblance to that of Opalinopsis, andthe resemblance must lie deeper in the organization than cell-boundaries. Compare the results obtained by artificial division in twosuch forms as Stentor and Hydra. The two courses of regen- 650 WHITMAN. [Vol. VIII. eration are so exactly parallel that one cannot fail to see atonce that the formative forces operate in essentially the samemanner with the one-celled as with the many-celled experiment, as described in his recent article, Micro-scopic Vivisection {Berichte der Naturforschenden Gesellschaftzu Freiburg, Vol. VII, Part i, 1893), illustrates well this Stentor was cut into three pieces, A, B, C, each of whichregenerated the missing parts within 24 hours. The anterior. Fig. I. — Regeneration of a Stentor cut into three parts, A, B, C. j/c = pulsatingvacuole. S = regenerating frontal field. end regenerated posterior end, and vice versa. The middlepiece regenerated both ends — the complicated frontal fieldwith its mouth, pharynx, long cilia, pulsating vesicle, etc., aswell as the simpler posterior region. Treat a Hydra in the same way and similar results will both cases the orientation of the parts will remain the sameas that of the whole. Gruber repeated the division of Stentorfour times in succession, getting perfect regeneration each No. 3-] THE INADEQUACY OF THE CELL-THEORV. 651 time, but smaller individuals, as no growth was experiment reminds one of the half- or quarter-sizedembryos obtained by separating the first two or four blasto-meres. Grubers highly interesting paper calls attention to the iden-tity in form and structural detail of the membranellae ofStentor with the so-called corner-cells
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