Miscellaneous, 241 



The second portion, which is supported by tlie basal joint {a), con- 

 sists of a first joint (d), which itself acts as a basal joint to the two 

 other antennae, and represents consequently the joint a of the whole 

 antenna. This first joint is inserted above the small globular joint b ; 

 it is enlarged at the extremity, and its form is the same as that of the 

 general basal joint ; like it, also, it presents two articulatory surfaces ; 

 one, directed downwards, bears the second antenna (2) ; the other, 

 turned upwards, serves for the articulation of the third antenna (3). 



The second antenna (2), or first supplementary antenna, is com- 

 posed of two pieces, namely an elongated joint, resembling in form 

 the joint c of the first antenna, and the club, which is composed of 

 seven lamellae, and is only 1 j millimetre in length. 



The third antenna (3) is composed, like the preceding, of an elon- 

 gated joint and a club ; the latter measures 2\ millimetres, and con- 

 sists Uke the preceding of seven lamellae. 



Thus, the right antenna is composed of portions which are repe- 

 titions of one another ; of a first normal antenna, of a second antenna, 

 grafted, as it were, upon the first, and of a third grafted upon the se- 

 cond ; only, in the latter the basal joint is wanting. We might also 

 say, that the primitive antenna bears a bifurcate supernumerary antenna. 



[After mentioning several cases of monstrosities by excess in Coleo- 

 pterous insects, described by various authors, and referring to the 

 theory proposed by M. Bassi (Ann. Soc. Ent. Fr. iii. p. 3/3) to ac- 

 count for these phoenomena, M. Lereboullet proceeds to give his own 

 views on this subject as follows : — ] 



Without pretending to wish to establish a theory of the mode of 

 production of these anomalies in the Articulata, I will remark, that, 

 in these animals, the appearance of the limbs takes place by a sort of 

 shooting or budding subject to determinate laws for each species, and 

 which is manifested, at a given period of development, on determinate 

 points of the surface of the body. It is this great law of centrifugal 

 or peripheric development which determines the number of joints of 

 which the antennae or the feet are composed, the form of each of the 

 joints, and the general form of the member. Now, the development of 

 these parts can only take place at the expense of the nutritive juice ; 

 it is the blood which contains the primordial elements of the organs, 

 or, to be more exact, furnishes the materials of which they are com- 

 posed. If we suppose now that from some cause there is a super- 

 abundance of blood in one part, there might result from it a hypers- 

 trophy of the organs ; but as this has not yet completed its evolution, 

 the same part repeats itself several times and in the same form, on 

 account of the primary law which presides at the development of each 

 piece, — a true 7iisus formativus ^\\\ch appears to run each organ into 

 a mould, which we may call specific, as it is always the same for the 

 same species and only belongs to it. Thus, for example, in the case 

 above described, the first joint of the abnormal antenna is larger than 

 the same piece in the normal antenna. There has therefore been ex- 

 cess of nutrition in this part, and we may suppose that in con- 

 sequence of this excess of nutrition it has formed several antennae 

 similar to one another. 



I believe, therefore, that in monstrosities by excess there is not a 

 Ann. ^ Mag. N, Hist. Ser. 2. Vol.ix. 16 



