200 QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 



concludes that the kidney is the specific excreting organ for 

 this substance, as for urea, but that in this the Malpighian 

 capsules take no part. The secretion is effected by the epi- 

 thelium of the convoluted tubes, which have a certain power 

 of reducing the indigo solution. The single tubes may act 

 quite independently of one another. The straight tubes 

 serve merely for conveying away the secretion when formed. 



The conclusions drawn as to the function of the kidneys 

 are that not all the constituents of the iirine are secreted in 

 the Malpighian capsules ; and Ludwig^s view, that the urine 

 as a whole is a filtrate from the blood in the capsules, is un- 

 tenable. If the results attained with indigo may be extended 

 to the normal urinary products. Bowman's view, that the 

 Malpighian corpuscles exude only water, with perhaps salts 

 of low atomic weight, must be adopted. 



Rods similar to those seen in the kidney are met with in 

 the ducts of the parotid and submaxillary glands, and those 

 of certain glands of the nose, but not in the submaxillary. 

 These glands, however, show no corresponding difference of 

 function. 



2. Spermatozoa. — Merkel publishes a preliminary notice 

 on the development of spermatozoa (* Centralblatt,' No. 5, 

 1874, p. 65). 



