Search -
Spolia maris. Contributions to the knowledge of Rhabdopleura and Amphioxus
Spolia maris Contributions to the knowledge of Rhabdopleura and Amphioxus Author:Edwin Ray Lankester Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAPTER II Contributions to the Knowledge of Amphioxus lanceolatus, Yarrell. It is now fourteen years since I published in the ' Quarterly Journal of Micro... more »sc. Science ' (vol. xv) some notes on the structure of Amphioxus. I have delayed publishing until the present date fuller illustrations of the facts then recorded, but have made use of my material in annually recurring lectures at University College. One statement made in the notes above referred to I am not able to confirm, and must withdraw. I refer to the supposed confirmation of Johann Miiller's statement (1) that there is a pair of apertures on either side of the oral sphincter (velum of Huxley). I stated that these apertures lead from the pharynx to the praoral space. Miiller had described them as leading into the metapleural canals. In reality there are no such apertures at all. The " brown funnels/' which were described in my original note, are the most important structures which I have now to illustrate. Curiously enough, they have escaped all subsequent observers with the exception of Mr. William Bateson (2), of St. John's College, Cambridge, who confirmed my observation as to their position and character, and has compared them very significantly with the " collar-pores" of Balanoglossus. My purpose on the present occasion, in addition to that of definitely exhibiting the position and form of the brown funnels, is (1) to furnish a few numerical data of importance for the anatomical discussion of Amphioxus ; (2) to correct some errors which appear to be current as to the existence or nonexistence of spaces of one kind and another in the body and gill-bars of Amphioxus; and (3) to submit some drawings which represent, in a semi-diagrammatic form, the structure of Amphioxus, not merely as seen in sections o...« less