NATURAL HISTORY OF THE STAR-FISH. 
217 
The following’ gives in brief the measurements of some of the largest stars found 
on the car during summer and fall. The asterisk ( # ) indicates that the specimen was 
not returned to the car, so that a smaller specimen was recorded on the next date. 
Date. 
Milli- 
meters. 
Date. 
Milli- 
meters. 
Date. 
Milli- 
meters. 
Date. 
Milli- 
meters. 
Date. 
Milli- 
meters. 
July 15 
3 
Sept. 5 
25 
Sept. 26 
34 
Oct. 
12 
38 
Oct. 25 
45 
July 18 
5* 
Sept. 5 
25 
Sept. 26 
33 
Oct. 
12 
36 
Oct. 25 
44 
July 24 
8* 
Sept. 5 
25 
Sept. 26 
33 
Oct. 
12 
35 
Nov. 5 
45 
July 2G 
9 
Sept. 5 
24 
Sept. 26 
31 
Oct. 
12 
35 
Nov. 5 
44 
Aug. 2 
11 
Sept. 5 
24 
Sept. 20 
80 
Oct. 
25 
54* | 
Nov. 5 
43 
Aug. 18 
18 
Sept. 5 
24 
Sept. 26 
30 
Oct. 
25 
51 
Nov. 5 
43 
Sept. 5 
27 
Sept. 5 
23 
Oct. 12 
42 
Oct. 
25 
50 
N ov. 5 
43 
Sept. 5 
20 
Sept. 26 
35 
Oct. 12 
40 
( let. 
25 
48 
N o' v. 5 
42 
Sept. 5 
26 
Sept. 26 
35 
Oct. 12 
40 
Oct. 
25 
45 
Nov. 5 
40 
On September 5 a number of specimens (19 in all) were selected and placed by 
themselves in another car, so that I might be sure to measure the same individuals on 
succeeding days; these were measured on six occasions, with the following results: 
Specimen. 
Sept. 5. 
Sept. 26. 
Oct. 12. 
Oct. 25. 
Nov. 5. 
Nov. 11. 
No. 1 
24 
35 
40 
47 
46 
41(?) 
2 
24 
31 
35 
40 
38 
41 
3 
20 
30 
35 
38 
38 
40 
4 
19 
29 
34 
38 
38 
39 
5 
19 
29 
33 
38 
38 
38 
6 
19 
28 
32 
37 
38 
38 
7 
18 
28 
32 
36 
38 
36 
8 
18 
28 
31 
36 
37 
36 
9 
18 
27 
31 
36 
37 
35 
10 
18 
26 
30 
36 
37 
35 
11 
17 
26 
30 
35 
37 
35 
12 
16 
26 
30 
35 
37 
35 
13 
16 
25 
29 
35 
34 
35 
14 
1G 
25 
29 
35 
35 
35 
15 
15 
24 
28 
34 
33 
34 
16 
15 
23 
28 
32 
33 
34 
17 
15 
21 
27 
30 
32 
33 
18 
14 
21 
25 
30 
32 
31 
19 
12 
21 
29 
31 
31 
It will be noticed that among these specimens, as well as among those in the 
original car, given in the first table, there is rarely any evidence of growth after 
October 25, but there is rather a slight decrease in size. On each occasion the 
measurements were made without referring to those of the preceding date, so that no 
personal prejudice might enter the results. For the most part the figures indicate a 
fairly uniform rate of growth among the different stars. In interpreting these figures 
there is one factor which is to be taken into consideration, namely, that star-fish 
over 20 mm. (sometimes less) are able to contract and expand, so that two careful 
measurements, taken within a few minutes of each other, may vary as much as 1 
or 2 mm. The measurements in the last three columns, therefore, indicate that the 
star fish in the car were of about the same size on November 11 as on October 25. 
The first measurement (41 mm.) under November 11 is doubtless au error. 
It may be inferred, from what has already been said, that at any time during the 
summer, after the stars are all set, there is a great difference in size among them. 
To illustrate this point, I arranged on August 18 a series of specimens taken from the 
car and from the seaweed, and photographed them at natural size, by laying them 
down on the sensitive paper (with a thin transparent film between), and then exposing. 
The variation in size is shown in fig. 20, the first 5 specimens having been taken from 
the car, and the last 5 from the seaweed. This variation in size is doubtless due 
much more to the difference in amount of food than to difference in age. 
