June 2, 1905.] 



SCIENCE. 



857 



roller, weighs 17 pounds, but works very 

 easily, indeed. 



The heating apparatus consists of a metal 

 frame supporting a copper jacket which 

 has a concavity on its upper surface just a 

 little larger in diameter than that of the 

 roller. This protects the surface of the 

 roller from contact with either the metal 

 or flame. This concavity could easily be 

 changed into a hot water bath for the roller, 

 if so desired. The lamp is a Jiorizontal 

 Bunsen burner tube with numerous small 

 openings. The roller does not require to 

 be heated between each pair of plates, and 

 thus when not in use it is readily rolled up 

 into the support in front of the bed plate. 



This whole apparatus is very solid, com- 

 pact, accurate and easy to adjust. 



Some Abnormalities of Growth Produced 

 hy Parasites on Alcyonaria: C. C. Nut- 

 ting, State University of Iowa. 

 In their 'Report on the Alcyonaria of 

 the Challenger Expedition,' Wright and 

 Studer described a new genus, Calypter- 

 inus, giving as a generic character a certain 

 tunnel-like structure formed by excessively 

 enlarged spicules, the tunnel being along 

 one side of the stem or branch. Later 

 Studer, in reporting on the Alcyonaria se- 

 cured by the Prince of Monaco 's yacht, de- 

 clares that this peculiar structure is due to 

 the presence of an annelid, and is patho- 

 logical in fact. A similar structure was 

 found by the writer in a species of Tenella 

 secured by the Albatross from Hawaiian 

 waters. The tunnel-like structures, with 

 the annelids inside, were shown by means 

 of lantern slides. 



In a new species of Dasygorgia from the 

 same collection the writer found certain 

 very greatly enlarged polyps which at first 

 looked like a form of dimorphism hitherto 

 unknown. Upon dissection, however, these 

 monstrous polyps were found to contain, 

 without exception, minute crustaceans, 



either embryos or some form of degraded 

 parasite. These were also shown by means 

 of lantern slides from photographs made 

 by the author. It appears that we have 

 here a condition of affairs in an animal 

 organism which bears a close analogy to the 

 production of 'galls' in vegetable tissues. 



The Origin of the Subclavian Artery in the 

 Chick: Wm. A. LocY, Northwestern Uni- 

 versity. (Based on the work of Mr. 

 Sabin. ) 



The subclavian artery in birds lies ven- 

 tral to the vagus nerve and vena cava; in 

 mammals it occupies a dorsal position with 

 reference to those structures. On this ac- 

 count the subclavian arteries do not appear 

 to be homologous as to origin in these two 

 classes of vertebrates. ' Hoehstetter was the 

 first in 1890 to clear the question by show- 

 ing that the definitive subclavian in birds 

 is of secondary origin. Prior to its appear- 

 ance there is a vessel arising from the 

 dorsal aorta, opposite the 15th mesodermic 

 somite, which supplies blood to the wing- 

 bud from the third to the sixth day of 

 development. On the sixth day the sec- 

 ondary subclavian arises from the ventral 

 end of the third aortic arch. This new 

 vessel passes backrw^ard and joins with the 

 primary subclavian artery, coming from 

 the dorsal aorta, and, from the sixth to the 

 close of the seventh day of development, 

 the wing bud receives blood from the two 

 sources. The primary subclavian then dis- 

 appears and the secondary subclavian re- 

 mains as the permanent one. 



Mr. C. G. Sabin, a graduate student in 

 Northwestern University, has traced with 

 great care the embryonic history of the 

 subcl avians in the bird and has illustrated 

 the same. His results agree closely with 

 those of Hoehstetter, except that he finds 

 the primary subclavian in earlier stages 

 than Hoehstetter, and observes that in the 

 early condition the subclavian arises inde- 



