170 ANNALS OF SCOTTISH NATURAL HISTORY 
| Nocot Young a 
: Young of young of | young o 
| No. broods Young of the Young of the young of the young of the young of 
+ (esa le nee young of 
| daysimSpeci lies oa Tamar ay a nT GW 1 Ramee ee ee ne ee ae 
mens. Ist end 3rd At 5th 6th 7th 1st end 1st 
J 
h rd 4th 5th 1st end 3rd 
brood. | brood. |-brood. | brood. | brood. | brood. | brood. | brood. | brood. | brood. | brood. | brood. | brood. | brood. brood.| brood. 
40 |5th=e |}3rda@} jandé1} rstcl| .. Be os .. |zst a 
50 | 6th=/|4thal!|3rd 41 |endcl| std} .. aa .. |2nda@2| rst 62 
| 60 | 7th=g|s5that| 4thé!| 3rd cll2ndd@}| rstel| .. .. |3rd@2 lend 62| 1st c2| .. Le lersba2 
7o | 8th=/|6thal| sth 41} 4thcl|3rddllendel| ist fl] .. | 4tha2| 3rd 62 andc?| tstd?) .. 2nd a3 | rst 63 
80 | oth=z }7thal| 6th 21| sth cl] 4th dl) 3rd el jond /}| rst g1| 5th a2| 4th 62) 3rd c2\ond d2| rst e2 | 3rd a3 |and 43} 1st c3| 1st a4 
Number of Daphnia at first = 10 | Anda@=  4,000xX20x5— = 4c0,cea 
atoz=the young of first » = 4,000\X 20% 4— se 2a ace 
10, or IOX20X9 = 1,800] ,, «= 4,000x20x3= 240;G00 
And @i— 200) 2017 © =) =| 25,000 5 @2= 4,000 X 20 x2— ee eee 
1 C1 =200!<20)< 6). . += 24,000 | _,,  ¢= -' 4,000 x20-e1— 80,000 
Ni iGs = 200.420. 5). i= 20,000 » @= 80,000x20x3— 4,c00,c00 
», @'=200xX 20x4. 25 =! 510,000 >» @= 80,000 x 20x 2— 3,200,608 
oy ci 200 < 20003 ) =) 12,000 5 ©=  80,000x 20x T= I,cogea 
ff S209 BOB a == 905000 5, @&'=1,600,000 x 20 x I = 32,000,000 
of) Pe AOD) 6 AOS p= 345000 Sane 
ne 42,600,000 
123,810 123,810 
Total number of specimens 42,723,810 
The above is a slightly extended and modified copy of a table prepared by my 
son, Mr. Andrew Scott. 
Though in the preceding remarks Daphnia pulex only 
has been considered, there are many others of the entomostraca 
equally prolific. But though the fecundity of micro-crustacea 
were considerably less than that shown, it would still be - 
sufficient to fill up in a short time even an extensive blank 
that some destructive but temporary cause may have produced. 
‘Full nature swarms with life; one wondrous mass.” 
COWPER. 
The natural habitat of the freshwater entomostraca is the 
still water of lakes, ponds, ditches, and those parts of streams 
or rivers where the current is slow and cumbered with water- 
plants: entomostraca may be found in all such places. 
Running water is not their natural resort, and when they 
happen to be in such a situation they are usually there 
against their will. Nevertheless an exodus of Copepoda such 
as that observed by Mr. Tullis is not unknown to those who 
leila ie AOA a8 2 igh 
