HARPER: BINARY FISSION AND SURFACE TENSION 165 
of the male gametes as they form, is not clear, though it is generally 
agreed that the cell arrangement in the bundle of male gametes is 
homologous with that of the young vegetative colony. 
Klein (’97) describes colonies of antherozoids in the form of hollow 
spheres. Stein (’78) had also observed them. Chodat (’02) reports 
plate-shaped individuals of Pandorina. These cases indicate how 
closely the plate-shaped and the spherical colonies are related physi- 
cally. The globular antherozoid bundles in Volvox may well be 
regarded as tending toward the vegetative and away from the sexual 
condition. That such changes should involve changes in surface 
tension and adhesion is quite conceivable, as the elongation of the 
antherozoid cell body must of course be a factor in determining the 
form of colony. The further study of the formation of these abnormal 
male colonies, especially, should throw light on the whole series of 
morphogenetic problems here involved. The facts as known are 
certainly quite in harmony with the view that such presumably easily 
influenced factors as adhesion and surface tension, combined with the 
more fundamental and ever-present incompatibility between the 
principles of binary fission and least surfaces, may be of determining 
significance in the transition from the plate-shaped to the three- 
dimensional globular form of colony with all its evolutionary sig- 
nificance. 
INDEX OF LITERATURE 
Cohn, F. Untersuchungen ueber die Entwickelungsgeschichte der mikroskop. 
Algen u. Pilze. Nova acta Leop.-Carol. 24 (1): Ior. 1854. 
Henfrey, A. Notes on Some Fresh-water Confervoid Algae. Trans. Mic. Soc. 
London, N.S., IV, p. 49. 1856. 
Hofmeister. Die Lehre von der Pflanzenzelle. Leipzig. 1867. 
Braun, Al. Bemerkungen zu Cohn’s Schrift ueber Volvox. Sitz.-Ber. d. Ges. 
naturf. Freunde zu Berlin, Bot. Z. 190. 1875. 
Braun, Al. Ueber einige Volvocineen. Sitz.-Ber. d. Ges. naturf. Freunde, Bot. Z. 
L895 1875. 
Cohn, F. Die Entwickelungsgeschichte der Gattung Volvox. Beitr. z. Biologie 
der Pflanzen 3: 93. 1875. 
Goroschankin. Die Genesis bei den Palmellaceen. Versuch einer vergl. Morpho- 
logie der Volvocineae. Nachr. d. Kais. Ges. f. Naturw. usw. Moskau, 16. 
1875. 
Sachs, J. Ueber die anordnung der Zellen im jiingsten Pflanzenteilen. 1878. 
Stein, Fr. v. Organismus der Infusionstiere. 3: I. 1878. 
Kirchner. Ueber die Entwickelungsgeschichte von Volvox minor. Cohn’s Beitrage 
3:95. 1879. 
Goebel, K. Grundziige der Systematik und speziellen Pflanzenmorphologie. 1882. 
Falkenberg. Die Algen. Schenk’s Handbuch, p. 284. 1882. 
Biitschli. Protozoa. Bronn’s Klassen u. Ordn. d. Tierreichs. 1. 1883. 
Klebs, G. Organization einiger Flagellatengruppen und ihre Beziehungen zu Algen 
und Infusorien. Arb. d. bot. Inst. Tiibingen 1: 339. 1883. 
