232 PROGRESS OF MICROSCOPICAL SCIENCE. 



telegraphic cables between the thyroidean colony and the metropolitan 

 cerebro-spinal axis. To continue the simile, the colony has itself an 

 autonomous system of telegraphy, the stations being represented by 

 numerous microscopic ganglia, with connecting branches which do not 

 pass outside the gland. The best means of examining the nerves of 

 the gland he finds to be, not hardening agents such as osmic acid, but 

 softening and disintegrating agents, and he has obtained good results 

 from maceration in water acidulated with acetic acid, and slightly 

 coloured with fuchsine. 



The Minute Anatomy of the Thyroid Gland has been very care- 

 fully worked out by Dr. E. C. Baber, who has been carrying on 

 investigations on this subject in Dr. Klein's laboratory. It seems 

 from an abstract of his paper, published in the ' Proceedings of 

 the Eoyal Society,' No. 166, that on injecting the lymphatics of this 

 organ with Berlin blue, by the method of puncture, they present 

 the following characters : Traversing the gland, chiefly in a longi- 

 tudinal direction, are large lympliaiic vessels provided with valves. In 

 direct connection with these, and permeating the gland in all 

 directions, is a dense meshwork of lymphaiic tubes and spaces. The 

 smaller lymphatic tubes run between individual gland-vesicles, the 

 larger between groups of the same. They accommodate themselves 

 accurately to the intervals left between the vesicles, and where the 

 intervals are larger they exj^and into irregularly shaped lymphatic 

 spaces. They present no appearance of terminating in blind extremi- 

 ties, as stated by some authors. Injections with nitrate of silver show 

 the lymphatic vessels, tubes, and spaces to be all lined with a 

 continuous layer of endothelial j)lates. During this investigation it 

 became necessary to study more carefully the iuteralveolar tissues. 

 This led to the discovery in them of a tissue which does not appear to 

 have yet been described. This tissue, which is designated by the 

 author by the name of "parenchyma," consists of large rounded cells, 

 each provided with an oval nucleus, found either singly or in groups 

 amongst the epithelial cells. From appearances presented by the 

 parenchymatous cells, the author concludes that they originate ex- 

 ternal to the vesicles by exerting pressure on the epithelial wall of the 

 vesicles ; they then produce a flattening and absorption of the same, 

 and finally make their way through it into the interior of the vesicle. 



The Structure and Development of Antedon rosaceus. — A very 

 splendid memoir on the anatomy and physiology of this Echinoderm has 

 been contributed to the Eoyal Society by Dr. Carpenter, and must be 

 referred to now by our readers, from the utter impossibility of abstract- 

 ing it without the plates which accompany the paper.* The paragraph 

 on the mode in which its food is digested may, however, be given. 

 Dr. Carpenter says that the food of Antedon consists, not of the large 

 bodies grasped and swallowed by ordinary Starfish, but of minute and 

 even microscopic organisms ; and that the so-called " tentacles " are 

 entirely destitute of prehensile power was long since affirmed by 



* 'Proceedings of the Royal Society,' Jan. 20. 



