. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. HYDROID COLONY GROWTH Observations on colonv f/rowth and expansion A. Overall pattern Some colonies were observed for more than two weeks, during which time they grew in length, accommodating elongation of the worm tubes, but did not change in overall pattern. Furthermore, nearly every one of hundreds of colonies studied throughout the summer and at intervals through the winter showed similar organi- zation regardless of the size of the colony and tube (except for colonies on very small tubes, as discussed below). Apparently
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. HYDROID COLONY GROWTH Observations on colonv f/rowth and expansion A. Overall pattern Some colonies were observed for more than two weeks, during which time they grew in length, accommodating elongation of the worm tubes, but did not change in overall pattern. Furthermore, nearly every one of hundreds of colonies studied throughout the summer and at intervals through the winter showed similar organi- zation regardless of the size of the colony and tube (except for colonies on very small tubes, as discussed below). Apparently the colony is in a steady-state devel- opmental pattern, where continuing growth and expansion do not result in a quali- tative change in FIGURE 3. Gastrozooid, with gonozooid, migrating on a glass microscope slide. Photo- graph, taken from the side, was printed from a 16 mm. film. Gastrozooid hypostome is in upper right; two tentacles are at lower right. Arrow points to "; The stolon (broken white lines) runs off to the left. B. Developmental cycle of polyps Gastrozooids arise through modification of a stolon tip at the rim of the worm tube. This stolon forms as a lateral branch from one of the parallel stolons just behind the tube rim. It does not transform into a polyp until after it has extended slightly beyond the tube rim. At this time there is a slight flattening of the tip in a plane tangential to the tube surface. Two tentacle rudiments first become visible as broad lateral wings on this stolon tip. As these elongate, their posi- tions shift towards the "front," where they eventually become spaced about 40°-70° from one another. This shifting is probably due to the more rapid growth of the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Labora
Size: 1883px × 1326px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
