10 Mr. E. Lovett on Abnormal Forms and 



103. — Abnormal Forms and Variations in the Animal Einqdoh. 

 By Edward Lovett. 

 (Read May 11th, 1892.) 



The following observations are compiled from notes made by 

 me from time to time, when I bad opportunities of doing a little 

 practical work amongst Insects, Crustacea, and Mollusca. 



Examples of deviation from tbe normal type are always inte- 

 resting, wbatever may be tbe cause of sucb deviation, and tbere 

 ai'e several, for example, albinism, melanism, mimicry (so-called), 

 deformity, and true variation, to which latter I wish specially to 

 refer. 



Albinism is tbe name given to that remarkable white form 

 which frequently obtains amongstmany animals, whilst melanism 

 is the exact reverse of this, being the dark or black variety. Mimi- 

 cry, or, to use a better though longer expression, the approach in 

 resemblance, through a long process of natural selection, of one 

 species to another, or to some other object, for the purpose of 

 self-interest, offensive or defensive ; mimicry, I repeat, appears to 

 come so very close to true variation that it is difficult to dis- 

 sociate it, though it is not my intention to deal fully with this 

 aspect of the subject, but more to the influence of other external 

 conditions in bringing about variations or deviations from the 

 type of the species subject to those influences. As regards what 

 may be called deformities, these can be dismissed altogether from 

 our consideration as being in no sense of the word true variations. 

 Deformities are either the result of imperfect development, acci- 

 dent, or monstrosity, and, if capable of reproducing their species 

 at all, which in the majority of instances is doubtful, would not 

 be at all likely to reproduce the aberrant features or peculiarities 

 which they themselves possess ; whereas true varieties possess 

 deviating characteristics which do not in any way interfere with 

 the functions of life, but, if anything, permit such functions to 

 be carried out with greater safety, and with more facilities, than 

 when the species in question was not in such complete accord 

 with its surrounding conditions. As examples of deformi- 

 ties may be instanced a decapod or ten-footed crustacean with 

 elei-en legs, an example of which is in my collection ; abnormal 

 growths of the limbs of crustaceans, which very frequently occur 

 through accident ; butterflies with hermaphroditic tendencies, or 

 with imperfect or too many wings, such as exist in many collec- 

 tions, and which, I regret to say, are considered of great value. 

 Amongst Mammalia and birds such deformities assume a variety 

 of repulsive forms, as may too frequently be seen at country 

 fairs ; such cripples are of no value in any way whatever, and 

 are only calculated to degrade the observer of them. 



