Page:The Last link.djvu/125

Rh cause the Gastrula arises from and passes through stages which exist as independent, permanent organisms among the Protozoa.

Needless to say this Gastræa-theory has been violently attacked in detail, with the result that various modifications of the Gastrula, until then undreamed of, have become known.

'Monographie der Medusen.' Jena, 1879-81. With 72 coloured plates.

'Reports on the Scientific Results of the Voyage of H.M.S. Challenger.' With 230 plates:

A short holiday spent on the coasts of the Red Sea produced the volume 'Arabische Korallen' (Berlin, 1876); and a longer trip to Ceylon has been described in 'Indische Reisebriefe,' of which the third edition