Die Methoden zum biologischen Nachweis der Androgamone AI und AII sowie der Gynogamone GI und GII werden beschrieben. Als Farbstoffe der Eier von Salmo irideus wurden Astaxanthin, β-Carotin, Lutein und Lactoflavin aufgefunden und quantitativ bestimmt. Astaxanthin, C40H52O4 (Schmp. 216°), ist GI-wirksam. Es aktiviert die Spermatozoen der Regenbogenforelle, wirkt chemotaktisch auf sie und ist Antagonist des im Sperma vorkommenden AI. Aus den Eiern wurde ferner ein thermolabiles Proteid gewonnen, das aus einem globulinartigen Protein + Phosphatid besteht. Es agglutiniert die Spermatozoen bis zu einer Verdünnung von 1:5 000 000 000. Das die Wirkung des Agglutinins (GII) aufhebende AII des Spermas ist thermostabil.

In the presence of vanadium, growth of Scenedesmus obliquus and Chlorella pyrenoidosa was increased five to sixfold as determined by dry weight, when cultured under autotrophic conditions for 7 days. The stimulation by vanadium decreased with increasing stability towards hydrolysis of the iron(III)-compounds added. Pentavalent vanadium (20 mug V/1 as NH4VO3) was able to overcome completely a limited iron-deficiency in the algae following growth in presence of 1.8 - 10(-5) m ferric chloride. Vanadium did not alter the iron uptake into the algal cells. 90% of offered 48V was taken up by Scenedesmus obliquus during 5 days of growth, and 21% thereof were found in the chloroplast fraction. In presence of vanadium, the chlorophyll formation was stimulated in Scenedesmus obliquus. This stimulation by vanadium was found to be light-dependent but occurred to a certain extent in the dark also. The main porphyrin of the yellow mutant 211-11h/20 of Chlorella vulgaris was identified as protoporphyrin-IX. The formation of this compound was stimulated by vanadium within 10 days up to 83%. The role of vanadium in the biosynthesis of chlorophylls is discussed.

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