Home >> Papers-from-the-department-of-marine-bio-volume-11 >> 3 Effect Of Temperature to Germ Cell Origin In Vertebrates >> Analysis of the Divisions

Analysis of the Divisions of the Starved Cassiopea

normal, weight, body, weights and body-weight

ANALYSIS OF THE DIVISIONS OF THE STARVED CASSIOPEA.

Various determinations made on the different parts of the body show that the water-content is practically identical in all the starved cassiopeas. Here also, as in the case of the normal animal, the um brella gives a slightly higher water value, owing possibly to the inclu sion of the stomach contents (water). The percentage of nitrogen in the solids also shows relations similar to those in the normal cassiopea; that is, the nitrogen-content is highest in the velar lobes and lowest in the umbrella, while that for the mouth-organs occupies an inter mediate position.

I have shown (in table 6) the loss of weight in body as the result of 21 days of starvation. We noted that in this series the cassiopeas lost on the average as much as 72 per cent of their initial weight, but as to whether they lost in weight proportionally in the different divisions of the body, or whether the loss was otherwise distributed in the three parts, I have found the following relations: For a final starved body-weight of 29.97 grams (table 6) the relative weights of the mouth-organs, umbrella, and velum are 18, 10, and 2 grams, respectively, when read from figure 1, while the corresponding observed weights were 17.16, 10.82, and 1.99 grams. Reducing these relative weights to ratios we obtain for the body-weight of 29.97 grams From figure 1, 9: 5: 1 From observations, 8.6: 5.4: 1 For the initial body-weight of 96.32 grains (table 6) of the animals subsequently starved to the weight just noted the ratios (from fig. 1) are 8: 5: 1. Considering the conditions under which the comparison of these data are made, these three ratios may be regarded as equiva lent and show that the ihree parts of the body have, as it were, reversed the process of growth during starvation. The strictly proportional loss in these three parts accounts for the normal appearance of the animals, even after they have lost as much as 62 to 80 per cent of their original weight.

The statement made in my preliminary report (1916) that "in the starved cassiopme the relative weights of the three parts coincide with those given by the normal cassiopea, which have a body-weight similar to the starved cassiopea at the end of the test, and not to the relative weights at the beginning of the experiment," should therefore be changed to a more general statement by omitting "and not to the relative weights at the beginning of the experiment," since the devia tions of the proportional values after starvation are so slight, whether these are compared with the proportions given by the normal examples having either the final or initial body-weights. More exact state

ments can be made after we have obtained a large number of data on both the normal and starved specimens.

Briefly summarized, the results of the observations made on the starved cassiopea are as follows: (1) In general the smaller cassiopea loses relatively more in weight than does the larger cassiopea.

(2) The percentage of water found in the entire body, as well as in the three different parts, is nearly the same in all sizes of cassiopea. However, the values of the water-content in the starved appear to be slightly higher than that found in the normal cassiopea.

(3) The nitrogen-content of the entire body is higher in the small than in the larger cassiopea, as in the case of the normal animals.

(4) However, the absolute amount of nitrogen found in the starved cassiopea is considerably higher than in the normal having the same body weight. It was noted also that, although high when compared with a normal specimen equal in weight to the starved animal, it is very low for the initial body-weight of the starved animal. This shows that the nitrogen has also been consumed during the period of starvation.

(5) The nitrogen-contents for the different parts of the body are similar in their relations to those found in the normal cassiopea.

(6) The loss in weight of the different parts is of such a character that their proportion in the starved remain similar to those in the normal cassiopea.