G. GENERAL NATURAL HISTORY AND ZOOLOGY. 315 



at was that the white blood of the invertebrates contained 

 nearly as much iron as the red blood of the vertebrates, and 

 that the plants exempt from green coloring matter, such as 

 fungi, contain iron, as is the case with other forms of vege- 

 tation ; also, that of all the nutritious substances consumed 

 by man, blood is certainly the richest in assimilable iron. 

 In Europe, however, it is only the blood of the pig that is 

 used as an article of food, that of oxen and other animals hav- 

 ing a peculiar odor which causes- its rejection. 6 B, May 

 27,1872,1353. 



DAVIDSON ON MORSE'S VIEWS OF THE BRACHIOPODS. 



Mr. Davidson, in commenting upon the views of Professor 

 Morse, in reference to the annelidan character of the Brach- 

 iopoda, takes occasion to dissent from the hypothesis, and 

 places the group in a class independent of the mollusca, al- 

 though most fairly related to them. He remarks that some 

 of the characters are rather puzzling, but that any inverte- 

 brates may be " annelidized" by overrating certain points 

 of their affinities. 15 A, Proc.Brit. Assoc, Aug. 31, 1872, 273. 



EMBRYOLOGY OF GORDIUS. 



M. Villot, in a recent communication to the Academy of 

 Science of Paris, describes what he considers to be the em- 

 bryonic structure of the Gordius, or hair worm. This is a 

 microscopic, cylindrical worm, scarcely 0.205 of a millimeter 

 in length, and 0.045 in width, in which a body, head, and tail 

 may easily be distinguished. The head is as broad as the 

 body, and perfectly retractile. It is armed with a triple 

 crown of large hooks, and is terminated anteriorly by a kind 

 of sucking-tube. This is stiffened by four strong stylets, 

 which serve as a frame. The head, in its movements of pro- 

 traction and of retraction, is like the trunk of the Echino- 

 rhyncus, and when exterior to the body the point of the hooks 

 is directed backward. The body exhibits numerous trans- 

 verse folds, very regular and close together, forming, as it 

 were, continuous rings. The tail is a little narrower than 

 the body, and separated by a deep constriction. It is also 

 distinctly annellated, and has four appendages toward the 

 posterior extremity, two small ones at the centre, and two 

 larger at the side. 



