PLATE 1 



EXPLAXATIOX OF FIGURES 



Fat-tissue cells from larvae of the honey-bee. X 330 



Figures 7 and 9, X 1000 



Figures 1, 2, 3, 6, and 7, iron-alum haematoxylin ; figure 4, safranin-gentian 

 violet mordanted with Gram's solution; figure 5, iron-alum haematoxylin and 

 eosin; figures 8 and 9, iron-alum haematoxj'lin and safranin. 



1 Worker bee larva fat-tissue cell, early larval stage B, showing nucleus 

 pushed aside by one large fat-vacuole, with others forming. 



2 Same as above, stage later, C, peripheral ring of fat-vacuoles forming, 

 nucleus in center undistorted. 



3 Queen bee larva fat-tissue cell, late larva, stage C; pressed out of shape at 

 the edge of a mass of cells, cut a little at one side of center. A precocious scatter- 

 ing of nuclear granules is taking place, before the fat-vacuoles have reached the 

 central nuclear area. 



4 An attenuated cell of early prepupal stage, D, queen larva, showing nuclear 

 dispersion of granules, and their developemnt into globules. In other sections 

 the granules may be seen in passage from the sides of the nucleus as well as from 

 the ends. The nuclear vesicle is apparently beginning to reform here along the 

 sides. 



5 Slighth' earlier phase than above of stage D, transforming queen larva, 

 nucleus actively dispersing granules of basophile material, ring of fat-vacuoles 

 pressing it centrally. A more spherical cell would show trabeculae of densely 

 staining material at other regions than the ends of the cell nuclei. Long and 

 narrow cells are chosen here for simplicity and definition of the cell conditions. 



6 and 7 early prepupal stage D, worker larva, cross-section of a cell of the 

 shape shown in figure 5, cut through one end of the nucleus, and an enlarged drawing 

 of the central region of the same. Centrally, the nuclear area still contains large 

 granules, interspersed with manj- smaller ones, and the whole is surrounded by a 

 characteristic ring of fat-vacuoles, with verj' sharply defined walls. Through 

 the interstices of these vacuoles nuclear granules are still passing. Peripherally 

 to this again, the central cytoplasm extends out into many small trabeculae through 

 the peripheral lightly staining cj'toplasm, to the marginal region of the cell. 



8 Cell from a queen larva, same stage as above, longitudinal section, and 

 figure 9, a higher magnification of one end of its nuclear region. The typical 

 condition of smaller fat-vacuoles and a more violent dispersion of granules, with 

 more attenuated and numerous trabeculae, is characteristic of the queen larva 

 as compared with the worker. Alost of the cells of the queen larva are even 

 more complex. Here again, as above, an elongated bi-polar cell was chosen, 

 for comparison with the typical bipolar cell of the worker. Extreme destaining 

 has obliterated the finer nuclear structures. 



596 



