836 SEC. 18. BIOLOGY. 



3899. Slaty discolouration of the mucous membrane of the 

 large intestine. 



Pietro Toninetti Pathological Institute, Berlin (Director, 

 Prof. Dr. Virchow). 



3900. Two Kidneys. 



Pietro Toninetti Pathological Institute, Berlin (Director, 

 Prof. Dr. Virchow). 



3901. Two Normal Brains. 



Pietro Toninetti Pathological Institute, Berlin {Director, 

 Prof. Dr. Virchow). 



3902. Bullock's Heart and Lungs. 



Pietro Toninetti Pathological Institute, Berlin (Director, 

 Prof. Dr. Virchow). 



3903. Histologica! Preparations for Teaching. 



C. Rodig, Hamburg. 



I. Collection of 150 drug preparations, in accordance with the pharma- 

 ceutical atlas of Professor Berg, adapted for pharmaceutical instruc- 

 tion. 

 II. Sixty anatomical plant preparations for teaching botany. 



III. Algae, fungi, and mosses. 



IV. Cereals in sections for agricultural teaching. 



3904. Sketch of an apparatus for investigating the Influence 

 of Temperature on the life of Plants and Animals. 



Dr. W. Velten, Physiologist, I. R. Station for Experiments 

 relating to Forests, Vienna. 



The apparatus consists of a box of zinc, with double partitions, the upper 

 and sides perpendicular thereto being replaced by parallel glass plates. The 

 space between the partitions must be filled with fluids, while that in the centre 

 is destined for the objects to be experimented on. The whole is surrounded 

 by a wooden cover suited to receive a refrigerator. The box is heated from 

 below, and the temperature remains constant by means of a thermo-regulator 

 brought into connexion with the apparatus. At the sides are openings into 

 which the hands should be placed, when encased in india-rubber gloves only, 

 in order to work without great change of temperature in the apparatus itself. 

 By means of the same apparatus the influence of various coloured light 

 can be determined as well as that of gas, &c. at different degrees of tem- 

 perature. 



3904a. Skeleton of a Dog, disarticulated and mounted in 

 such a manner that every bone can be separately removed for exa- 

 mination. Prof. Huxley, F.R.S. 



3904b. Typical Parts of the Skeletons of a Cat, a 

 Duck, and a Codfish, disarticulated and mounted, to show the 

 chief modifications of the vertebrate endoskeleton. 



Prof. Huxley, F.R.S. 



