ANIMAL EXPERIMENTS 169 



Surface Details and Peripheral Outlines. In addition to the term 

 smooth, the following surface details and peripheral outlines are dis- 

 tinguished. 



Alveolate, marked by depressions so that a somewhat honeycombed 

 appearance results. 



Punctate, dotted with punctures like small pinholes. 



Bullate, irregular elevations somewhat resembling a blistered sur- 

 face. 



Vesicular, looking like small vesicles, and due to gas formation. 



Verrucose, wart-like, with papillary prominences. 



Squamous or scaly, covered with scales. 



Echinate, beset with pointed prominences. 



Papillate, beset with nipple-like prominences. 



Rugose, presenting short, irregular folds, in consequence of the 

 shrinkage of the surface growth. 



Corrugated, arranged in long folds. 



Edges. The edges of the colonies are described as entire when 

 there are no divisions and no serrations; as undulate when the outlines 

 are wavy; as repand when they are like the border of an open umbrella; 

 as ciliate when they show hair-like extensions. 



Details. The finer internal details of the colonies are studied on 

 microscopic impression preparations, and the following descriptive 

 terms are used: 



A reticulate structure shows the form of a network like the veins of 

 a leaf. 



Areolate, divided into rather irregular or angular spaces by more or 

 less definite boundaries. 



Gyrose, marked by wavy irregular lines like the convolutions of 

 the brain. 



Marmorated, marked like marble. 



ANIMAL EXPERIMENTS. 



Animal experiments are frequently made in order to obtain bac- 

 teria in pure culture, to identify pathogenic bacteria beyond doubt, 

 to test methods of disinfection or sterilization, to control the atten- 

 uation of vaccines, to obtain immune sera, etc. To obtain a pure 

 culture of glanders from an open lesion due to the Bacillus mallei, 

 it is generally necessary to inoculate a male guinea-pig in the 

 particular manner described in the chapter on glanders. The inocu- 

 lation of a guinea-pig or a mouse makes the rapid diagnosis of a 

 doubtful case of anthrax possible; similarly, guinea-pigs must be 

 inoculated in order to ascertain whether pasteurization has killed 

 tubercle bacilli in milk. After the preparation of anthrax vaccines it 

 is necessary to estimate accurately the attenuation of the bacilli by 

 injecting them into mice, guinea-pigs, and rabbits. When testing 



