[127]. ‘Entwicklung der Dipteren.’ Leipzig, 1864.
[128]. ‘Zeitschr. f. wiss. Zool.’ Bd. XVI. p. 389 (1866).
[129]. ‘Compt. rend.’ Nov. 13, 1882.
[130]. Grobben, ‘Arbeiten d. Wien. Zool. Instituts,’ Bd. II. p. 203.
[131]. Bütschli, ‘Zeitschrift f. wiss. Zool.’ Bd. XXIII. p. 409.
[132]. ‘Science,’ vol. iv. No. 90, 1884.
[133]. Among unicellular organisms, encysted individuals are often called germs. They sometimes differ from the adult organism in their smaller size and simpler structure (Gregarinidae), but they represent the same morphological stage of individuality.
[134]. Compare Bütschli in Bronn’s ‘Klassen und Ordnungen des Thierreichs,’ Bd. I. p. 777.
[135]. Gustav Jäger, ‘Lehrbuch der Allgemeinen Zoologie,’ Leipzig, 1878; II. Abtheilung. Probably on account of the extravagant and superficial speculations of the author, the valuable ideas contained in his book have been generally overlooked. It is only lately that I have become aware of Jäger’s above-mentioned hypothesis. M. Nussbaum seems to have also arrived at the same conclusion quite independently of Jäger. The latter has not attempted to work out his hypothesis with any degree of completeness. The above-mentioned observations are followed immediately by quite valueless considerations, as, for instance, that the ontogenetic and phyletic groups are in concentric ratio! The author might as well speak of a quadrangular or triangular ratio!
[136]. [Facts of the same kind are also known in the Vascular Cryptogams, Muscineae, Characeae, Florideae, etc.—S. S.]