374 R G. HOSKINS 



and one experimental animal which survived the operation for at least 

 a month. In subjects from 14 of these litters bony changes developed 

 which were studied both radioscopically and at autopsy. Within two 

 or three weeks the changes began to be apparent. The bones in the legs 

 of the thymectomized subjects seemed softer and more flexible and the 

 gait became more or less awkward. Later the legs in some cases became 

 bowed or bent to an extreme degree. The bones were more easily frac- 

 tured in the thymectomized than in the control animals ; callus formation 

 was more extensive and subsequent healing processes took place less ef- 

 fectively. These changes suggested to the author that he was dealing with 

 a condition of experimental rickets, but he concluded, on account of the 

 relatively short duration and the generally mild character of the changes, 

 that such was not the case. Basch concluded that the thymus is not a 

 gland indispensable to life, but that it exercises a transitory function dur- 

 ing the earlier months of life, when the processes of growth and calcifi- 

 cation of bone are most active. As regards the nervous system, he found 

 that the peripheral nerves were more excitable to galvanic current in 

 the experimental than in the control animals. He also frequently noted 

 convulsions. From these findings he concluded that the thymus plays an 

 important role in the etiology of tetany. Park and McClure have sub- 

 jected Basch's data to careful analysis and have concluded that the changes 

 which he reported following thymectomy might be due partially to inad- 

 vertent differences between experimental and control conditions, and 

 partly to defective hygienic conditions. They publish a photograph of a 

 young dog which developed a gross appearance very similar to that de- 

 scribed by Basch and which was due merely to close confinement. 



Results somewhat similar to those of Basch were repOTted by Soli, 

 MacLennan, Sommer and Florcken, and Ranzi and Tandler. While 

 the findings were not consistent in details, they were regarded as indicating 

 that the thymus plays a fairly important role in the earlier stages of 

 postnatal skeletal development. 



The work of Klose and Vogt and of Matti, which more or less con- 

 firmed and supplemented that of Basch, has also been very widely quoted 

 and forms the basis of most text-book discussions of thymus function that 

 have appeared in recent years. 



Klose, who worked more or less in collaboration with Vogt, has pub- 

 lished very voluminously upon the effects of thymectomy. His experi- 

 mental animals included several species, but his best-known work was done 

 with dogs. The reports of his findings are so inconsistent among them- 

 selves and so lacking in specific details as to render an evaluation of them 

 difficult. Klose and Vogt describe the following changes as characteristic 

 of thymectoniy. Most striking results were secured when the thymus was 

 removed between the tenth and fourteenth days of life. From two weeks 

 to two or three months after the operation occurred the so-called "latent 



