. Bulletin of the British Museum (Natural History). EVOLUTIONARY TRENDS IX CAPITATE HYDROIDS AND MEDUSAE 459 of this group at Plymouth from 1936 to 1940. the ultimate aim of which he envisaged as a single classification of hydroids and their medusae. I also wsh to acknowledge with gratitude the encouragement I received from the late Edgar J. Allen, , the late Stanley W. Kemp, , and Dr. F. S. Russell, ! !,' during the time I was a member of the scientific staff of the Plymouth Laboratory! This paper could not have been witten, however, without the many facihties gra
. Bulletin of the British Museum (Natural History). EVOLUTIONARY TRENDS IX CAPITATE HYDROIDS AND MEDUSAE 459 of this group at Plymouth from 1936 to 1940. the ultimate aim of which he envisaged as a single classification of hydroids and their medusae. I also wsh to acknowledge with gratitude the encouragement I received from the late Edgar J. Allen, , the late Stanley W. Kemp, , and Dr. F. S. Russell, ! !,' during the time I was a member of the scientific staff of the Plymouth Laboratory! This paper could not have been witten, however, without the many facihties granted to me at the British Museum (Natural History), and, in particular, I wish to thank Sir Gavin de Beer, , for much encouragement. I am very grateful to Professor Hjalmar Broch for many stimulating discussions in Oslo, in September, 1955, but I do not wish to imply that he is in agreement with all or any part of this paper. I also wish to thank Dr. Marta Vannucci for reading the manuscript and for suggestmg the inclusion of Figure 58 and my colleague Mr. Ernest White for much , assistance in the preparation of the report. Other acknowledgments are given in the I text. 2. EVOLUTION IN THE POLYP AND DIVISION OF LABOUR 1(a) Evolution in the polyp Sessile colonial invertebrates are generally considered to have arisen from free swimming solitary individuals which have adopted a sedentan' habit and have. Fig. 3. Asyncoryne ryniensis Warren, a colonial hydroid with scattered moniUform body tentacles and an oral whorl of short capitate tentacles (redra^^^ from \\'arren, igo8). ' j later become colonial animals. This natural outcome of the adoption of a sedentary I habit is an axiomatic principle which applies also to the Hydrozoa and it is therefore ' surprising that Kramp (1949) suggests that the solitary Corymorphidae are derived from colonial forms like Asyncoryne (Text-fig. 3). This is quite unlikely to have. Please note that these images are extracted from scanned page ima
Size: 1411px × 1770px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., 1957, boo, bookauthorbritishmuseumnaturalhistory, bookcentury1900
