1584 Journal of Applied Microscopy 



Piana found accessory thyroid glands in sixty-six per cent, of all the dogs he 

 examined. These are to be sought for in the neighborhood of the aorta. One 

 of Sultan's cases shows how readily they may be overlooked. He examined, 

 microscopically, the lymph nodes from the arch of the aorta, and not until he 

 had looked over many sections did he find an island of typical thyroid tissue. It 

 partially surrounded a lymph-node and he likened it to a skull-cap. 



In cats, accessory thyroids are rarely found. j. h. p. 



Neumann, E. Das Pigment der braunen In his Studies of the pigment of brown 

 Luna;eninduration. Virchow's Archiv fiir . , ^. r ^i i xt 



pathTAnat., 161: 422-435, 1900. induration of the lung, Neumann never 



observed the formation of melanotic 



pigment from haemosiderin. Granules with a black center and a periphery 



more or less the color of haemosiderin were seen. He regards these bodies as 



particles of carbon-dust which have been incrusted with haemosiderin. He also 



observed bits of carbon with colorless peripheries. Both the colored and the 



colorless borders gave the iron reaction equally well. The author is inclined to 



regard this colorless modification as the last stage in the transformation of the 



blood pigment which terminates in its complete disappearance through resorption. 



Neumann found these peculiar pigment bodies in the bronchial lymph nodes 



as well as in the lungs. 



The haemosiderin is formed from the red blood corpuscles. There is first a 



diffusion of the haemoglobin, and later the pigment separates itself out of the 



solution. J. H. p. 



GENERAL PHYSIOLOGY. 



Raymond Pearl. 



Books and papers for review should be sent to Raymond Pearl, Zoological 

 Laboratory, University of Michigan, Ann Arbor, Mich. 



Loeb, J. On an apparently New Form of The author found that when the gas- 

 Muscular Irritability (Contact Irritability?) . 1 r r • ^ • 

 produced by Solutions of Salts (preferably trocnemius muscle of a frog IS put in 

 Sodium Salts) whose Anions are Liable to certain salt solutions in a Strength of 1 

 form Insoluble Calcium Compounds. Amer. , , r ^1 1. • o ^ in 

 Jour. Physiol. S: 362-373, 1901. g^am molecule of the salt in b to 10 



liters of water, and, after being sub- 

 jected for a time to the action of this solution, is brought back into air or certain 

 other substances, it goes into a tetanus or performs a series of strong contrac- 

 tions. This apparently new irritable phenomenon is provisionally considered as 

 " contact irritability." The substances other than air which produce the con- 

 traction when the muscle is passed from the salt solution into them are COo, oil, 

 2n sugar solution, glycerine, chloroform, toluol and probably mercury. The 

 salts whose solutions bring about the contact irritability are, with a single excep- 

 tion, sodium salts ; viz., sodium fluoride, sodium carbonate, Na2HP04, sodium 

 oxalate, sodium citrate and sodium tartrate. In addition to these (NH4)2 SO4 

 has the same effect. The anions of these sodium salts produce insoluble calcium 

 compounds and it is to the presence of these in the surface layers of the muscle 



