180 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY, 
7, Absorption by Mesenchyme. Only of late years have we come 
fully to appreciate the great róle played in ontogeny by the devour- 
ing capacity of mesenchyme. It is now 
fully established that such migratory pro- 
toplasmic bodies — phagocytes — are the 
most important agent in the degenerative 
processes which larve undergo in their 
h metamorphoses. 
Fra. 9. NECTARE RER ^: 
This is well shown in Insects (Figure 
10), in Bryozoa probably, in Ascidians, and in the frog. 
The secreting activity of mesenchyme has already been classed under 
general processes, No doubt mesenchymatous cells perform various 
US e 
ES 
Fia. 10. 
other functions in the body besides transportation, digestion, and secre- 
tion, but these either have little effect on the form or concern only 
histogenesis, 
II. OwrTocENETIO Processes OCCURRING IN ELONGATED PROTOPLASMIO 
Bopnigs — Fires, ÜünkADs, Corps, TUBULES. 
"alling under this head we may recognize, first, certain general 
changes due to growth, such as increase in length or in thickness. 
These may affect either the whole body or its parts, and may lead 
to a diminution or increase in sizo. 
Fig.9. Section through the transported bud of Dolchinia, showing the amoboid 
transporting cell. (See K. & H., Fig. 829.) 
Fig. 10. Sections through the abdominal imaginal disks of the hypodermis of 
Musca. A, from the larva. B, from the young pupa. In B the phagocytes (p.) 
are in the act of devouring the larval hypodermis (h.), which is replaced by the 
superficial growth of the imaginal disk (d.). K. & IL, Fig. 530. 
