16 XVI. Coelenterata. Hydroidea und Acalephae 



to occur. 2. That in regenerative processes there is often associated 

 the development of pigmentary substances which seem to have no 

 direct function in relation thereto. 3. That in many cases there follows 

 a more or less active excretion and elimination of portions of the 

 pigment in qiiestion. 



Hargitt, €has. W. {%). Regeneration in Scyphomedusae. — The 

 American Naturalist Vol. 38 (Nos 451—452) p. 517—519. Boston 1904. 



The series of experiments of which this abstract furnishes the 

 barest outhne was undertaken with a view to ascertain the compa- 

 rative capacity of Scyphomedusae to reproduce lost parts, such as 

 bits of the various parts of the body which might be lost by the usual 

 exigencies of the struggle of life. The experiments comprised some 

 three phases of regenerative energy: — First, the general ability to 

 recover from such injuries as rents of the umbrella, etc. ; second, regene- 

 ration of such organs as oral appendages; third, ability to regenerate 

 such specialized organs as the sensory bodies. Versuchthiere : Rhizo- 

 stomen bis zu 125 mm Durchmesser. The experiments clearly prove 

 the capacity among these organisms for regeneration of organs er 

 parts of Organs, from the more generalized sort to the most speciaUzed, 

 and that with approximately similar readiness. 



— (3). Regeneration in Rhizostoma pulmo. With 6 Figures. — 

 The Journal of Experimental Zoology Vol. 1 (No. 1) p. 73 — 94. 

 Baltimore 1904. 



I. Introductory. The primary object of the experiments was to 

 test the regenerative capacity of the Scyphomedusae and to Institute 

 certain comparisons between these results and those obtained by 

 similar experiments previously made upon the Hydromedusae. II. Ex- 

 perimental. The experiments were directed to three ends, namely 

 to determine: 1. The capacity of the medusae to reproduce lost parts, 

 or to recover from such injuries as might ordinarily happen to them 

 in a State of nature, such as the battering effects of waves, the injuries 

 inflicted by enemies, etc. 2. The comparative powers of the various 

 regions to regenerate, or in other words, the relation of the regenerative 

 capacity to liability to injury. 3. The capacity to regenerate such 

 highly specialized organs as rhopalia, or other sensory structures. 



III. Abnormalities. Sind selten. Nie erschien ein Tentakel statt 

 eines Rhopahums. Stellung zu UexküUs Versuchen von 1900. 



IV. Histology. 



— (4). The Early Development of Eudendrium. — Zoolog. 

 Jahrb. Anat. Bd. 20 (1904) p. 257—276, t. 14—16. 



Material aus Woods Holl (Juni, Juli, August) und Neapel (Mai, 

 Juni). Methoden. Origin of the cells (Literarisches; eigne Beob- 

 achtungen an Eud. racemosum, dispar und ( ? ) tenue und capillare ; 

 growth of the egg in Eudendrium, und Vergleich mit Hydra, Campa- 

 nularia, Pennaria, Distichopora, Clava [Harm 1902]). Early Deve- 

 lopment (Amitosis, und Vergleiche). Formation of the Ectoderm 

 (Glandulär cells, Interstitial cells). Entoderm Formation. Life 

 History of the Planula (Abnormalities). 



