. Gleanings in bee culture . Fig. 6.—a fiber of fascicle muscle: t, trachea. of development. Their structure is similarto the texture of the striate muscles of thevertebrates. One may discern a well-distin-guished longitudinal striation and trans-verse striation not less characteristic. Thelongitudinal striation is due to the greatnumber of fine fibrils, forming a transverse striation owes its origin tothe fact that each fibril is composed ofsheaves of more or less refraction. Pig. 7shows, in a transverse section, the few nuclei are scattered rather regu-larly between the
. Gleanings in bee culture . Fig. 6.—a fiber of fascicle muscle: t, trachea. of development. Their structure is similarto the texture of the striate muscles of thevertebrates. One may discern a well-distin-guished longitudinal striation and trans-verse striation not less characteristic. Thelongitudinal striation is due to the greatnumber of fine fibrils, forming a transverse striation owes its origin tothe fact that each fibril is composed ofsheaves of more or less refraction. Pig. 7shows, in a transverse section, the few nuclei are scattered rather regu-larly between the fibrils, which are notclearly shown in Fig. 6, but visible in There is no sarcolemm around the fasci-cle, but a multitude of tracheae penetratebetween the fascicles. For example, seeFig. 8, showing a transverse section of thebreast of a drone. Fig. 9 shows a great mag-nifying of these tracheae, whose walls arestrengthened by minute chitinous ^From those tracheal branches emerge a. Fig. 8.—Transverse section of drone breast: 1, leva-tor of wing: d, depressor of wing; b,?basis of wing;oe, oesophagus: g. ganglion. great number of extremely fine air-tubes,like little trees, sending their boughs intothe interior of the fascicles. In Figs. 8 and9 only the chitinous rods are impregnatedwith silver by a special method of the finest air-tubes do not contain anyof those chitinous rods, nothing is seen ofthem in the photos. If they too had beencolored the figure would show nothing buta thick web of black lines. The exchangeof oxygen and carbonic acid takes place onlyin those minute air-tubes. The exceedingly rich supply of the flightmuscles with tracheae proves the great im-portance of the gas exchange in the , the task of the flight muscles isenormous, the flight of a body heavier thanair requiring great mechanical labor. De-liberating on the quickness of the movementof the four wings, one may conceive thatthe rather simple-structured tube mu
Size: 1405px × 1778px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectbees, bookyear1874
