(mit Ausschluss der Siphonophora) für 1904. 15 



welche schon länger als einen Tag im Aquarium gelebt hatten, vor- 

 gefunden". [Aequorea Forskalea 1892, Arch. f. mikr. Anat. Bd. 40, 

 p. 248]. Aus dem übereinstimmenden Vorkommen von pluripolaren 

 Bildern in Geschwülsten und in vergifteten Zellen lassen sich keine 

 bestimmten Folgerungen ziehen. 



Hargitt, Charles W. (I). Some unsolved problems of organic 

 adaption. Address of the vice-president and chairman of Section F, 

 Zoology, St. Louis meeting, 1903. — Science (N S) Vol. 19 (1904) 

 p. 132—145. 



I have chosen to restrict my discussion chiefly to problems of 

 coloration among lower invertebrates, including incidental references 

 to correlated subjects, and the probable limitations of color as a factor 

 in organic adaption . . . Color in nature is due to one of two causes, 

 or to a combination of both, namely: (1) What has been termed optical 

 or structural conditions, such as diffraction, interference or uneqal re- 

 flection of light . . (2) What are known as pigmentary colors, due to 

 certain material substances lodged within the tissues of animals or 

 plants which have the property of absorbing certain Clements of light 

 and of reflecting others, and thereby producing the Sensation of color. 

 Betrachtungen über die Entstehung und Entwicklung der Pigmente, 

 und deren Beziehung zur Farbe der Organismen. Die Betrachtung 

 der Coelenteraten verspricht besonders fundamentale Schlüsse zu 

 ergeben, zumal wenn sie künftig mehr experimentell befragt werden 

 als bisher geschehen ist, p. 137 — 140. Hydroiden: Obelia, Halecium; 

 Eudendrium, Pennaria, Corymorpha. Höhere Färbung gewöhnlich 

 mit der development of the sexual products, oder mit der season of 

 reproductive activity verbunden. The most marked development of 

 color zeigt die Meduse, die sexual phase. Pigmentirt sind Gonaden, 

 Magen, Verdauungskanäle, zuweilen Tentakel und Sinnesorgane. 

 Bei Scyphomedusen we find as just suggested a more copious develop- 

 ment of color. Auch hier die deposition of pigment along the lines 

 of most active metabolisme. Korallen. Siehe A unter Gonionemus, 

 Cyanea, Dactylometra. — What answer shall we make to ourselves 

 concerning the significance of the multiform colors more or less general 

 among members of the coelenterata ? Dies der springende Punkt des 

 Problems, p. 141 — 143. Natürliche Auslese genügt nur begrenzt zur 

 Erklärung. Two, and only two, other methods of explanation have 

 secmed to me to afford a reasonable account. First, that it is due 

 primarily to the normal course of metabolism, during which color 

 appears as one of its many expressions. Darwin, Geddes & Thomson. 

 The second factor hängt damit zusammen. It is to the effect that 

 certain pigments are products of waste in process of elimination. 

 Hydrozoa: (Driesch, Loeb, Morgan, Stevens) ihr Pigment ist nicht 

 nur von besonderer Wichtigkeit, sondern auch really a waste product. 

 Ebenso bei Scyphozoen. Es ergiebt sich 1. That in all regenerative 

 processes a very marked degree of metabolism is involved, whether 

 in the mere metamorphosis of old tissues into new, or in the direct 

 regeneration of new tissues by growth processes, both of which seem 



