208 PROCEEDINGS OP THE [June, 1888. 



mous number of eggs which they produce, 68,000 having been counted in the 

 roe of a single female herring. This great productiveness alone prevents their 

 extermination, as, it has been computed, not more than one-tenth of one per 

 cent of the eggs escape the dangers to which they are exposed and arrive at the 

 mature state. The minnow, on the other hand, produces but a comparatively 

 limited number of its offspring, 125 being the largest number that I have 

 counted from a single minnow. If these were produced in the egg condition, 

 the species would probably soon become extinct. The ponds where the min- 

 nows are found are crowded with carnivorous insects and their still more rapa- 

 cious larvje. Frog-s and newts abound and, by no means the l«ist consideration, 

 the minnows themselves, which attack and devour everything which they can 

 overcome. Such is the rapacity of the minnow, that, after an aquarium is 

 once established, and the fishes have become acciistomed to their new condi- 

 tions, it is almost impossible to add any more specimens of any kind to the 

 collection. On one occasion, I added to an aquarium which I had kept about 

 sis months, two gold fishes about three inches in length. Although the lar- 

 gest minnow in the tank measured scarcely one and one half inches, still at the 

 end of a few hours one of the golden carps was dead and the other, although I 

 took it out and placed it in a separate tank, died soon afterwards. The min- 

 now's method of attack was to seize the gold fish by the tail, fins, or even 

 scales, and worry it to death. A tadpole, which I introduced in like manner, 

 was also soon destroyed, its tail being torn off in bits, although the tadpole was 

 larger than any six of its assailants. 



The danger then, to the immature minnow being so great, nature protects 

 it by developing it from the ova before parturition, and it is enabled at once to 

 make efforts to escape from the many dangers which surround it. 



1 cannot leave this subject without calling attention to the important theory 

 which the ovo- viviparous reproduction of the minnow dispels. The fresh wa- 

 ter minnow is found in almost every pond, puddle, or brook which has been in 

 existence any considerable length of time. The accepted theory accounting for 

 this is that the ova of the minnow is dropped in the water by aquatic birds. 

 The ovo-viviparous reproduction of this fish makes this theory impracticable, 

 as the young minnow cannot survive being taken from the water more than a 

 few minutes. 



Other theories may account for the minnow being found in some of the 

 ponds. No doubt the overflow of ponds and brooks may carry the fishes to 

 ponds in their neighborhood, but this theory could not account for the minnow 

 being found at Holbrook's place and near the Jewish Cemetery, both of which 

 are 15 miles from any body of water where fresh water fishes are found. 



In isolated cases also, fishes bave been known to descend with a heavy shower 

 of rain, having probably been carried upwards by a kind of water-spout ; but 

 this also will account for but very few cases. 



In August, 1887, the pond at Holbrook's place had completely disappeared, 

 owing to continued drought. This year, I have examined the water each month 

 and have thus far foand no fishes. One of the theories, accounting for the oc- 

 currence of fish in ponds that have been dried up, is that the ova is preserved 



