328 INEZ WHIPPLE WILDER. 



easily moved about. Moreover, owing to the fact that the adult 

 Desmognathus occasionally feeds upon the larvae, I have found 

 it safer for the latter to be kept in separate shallow receptacles, 

 such as glass crystallizing dishes, equipped with a little earth 

 covered with water to the depth of a few centimeters, and con- 

 taining a quantity of decaying, slime-covered leaves which have 

 been transported to it from the natural habitat of the larvae. 

 Such an arrangement, if kept tightly covered to prevent evapo- 

 ration, will support the larvae in a normal condition for months 

 without further care. 



The usefulness of Desmognathus as material for the various 

 phases of introductory research work cannot be over-emphasized. 

 As Wilder has pointed out, the large size and the unpigmented 

 nature of the egg render it excellent material for the study of 

 general amphibian embryology. The small size of the larvae 

 (from 15 to 30 mm. in length), and their long continuance in the 

 larval state, make them particularly valuable material for the 

 introduction to methods of study by serial sections, since the 

 specimens are not only small enought to decalcify easily and 

 section beautifully but are large enough and enough like the 

 adult in their general anatomy to also lend themselves readily to 

 study by dissection, and by the numerous methods of injecting 

 and selective staining followed by clearing in toto. Studied in 

 this way it furnishes, pedagogically, an excellent means of 

 transition from the study of the gross anatomy of larger verte- 

 brate forms to the study both of their histology and their earlier 

 embryology. Thus it bridges a gap which it has often been 

 customary in college courses to make at a jump which too often 

 lands even the able student in a region of mystery. As material 

 for the study of adult anatomy, also, Desmognathus is a con- 

 venient form, the larger specimens being quite large enough for 

 ready dissection, and not too large to use with the dissecting 

 microscope for finer details, while both the large and the small 

 adults may be readily decalcified and sectioned for the microscopic 

 study of their structure. Moreover the species with its suc- 

 cession of terrestrial and aquatic stages, its lungless condition and 

 other peculiarities of structure, presents a number of little 

 physiological and anatomical problems, the working out of which 



