MEMOIRS OF THE KATIO^TAL ACADEMY OF SCIElsCES. 
55 
The first author to suggest the derivation of Lepidoptera and the Trichoptera from a common 
stem form was A. Speyer.^ He speaks of the great similarity of the venation of the trichopterous 
wings to those of the Hepialidje, Cossidm, Micropterygidm, and to the hind wings of the Psychidm, 
though allowing that there is no Trichopteron whose venation entirely agrees with that of any 
Lepidoi)tera. He points out the fact that there are certain moths whose pup® have free limbs, as 
Heterogenea, Adela, and Micropterys, and that members of both orders spin a cocoon. He refers 
to the dissimilarity in tlie month-parts of the two orders, the maxilhe and labium, but does not 
specially refer to the distinction in shape between the maxilhe of the two orders. Speyer does 
not believe that the Lepidoptera directly descended from the Trichoptera, but that they had a 
■common origin, the latter being the earlier to appear, their remains occurring in lower geological 
strata.2 He thinks this common stem-form in the imago state had through disuse slightly 
developed biting mouth parts; that they took little or no nourishment, like the moths. The 
duration in the adult life was probably short, and the ancestors of the Lepidoptera were in the 
larval state aquatic, like caseworms. He suggests that the outer lobe of the maxilhe were at 
first simple in shape, but in the course of time by adaptation to the slowly increasing depth of 
tlie corollas of flowers, became a hollow sucking organ. This view was also held by 11. Midler in 
1809, who claimed that “ There is the closest affinity between the Phryganeid® and Lepidoidera, 
and the Phryganeid® have the buccal organs precisely in that rudimentary state whicli we 
should presuppose appropriate to the primordial race or type of Lepidoptera.'^ Muller also claimed 
that both Lepidoptera and Phryganeid® proceeded from a common stock. (Amer. Nat., v. 288, 
1871). 
In a review entitled “The position of the caddis flies’’ (Amer. Nat., v, 707, 1871) wc pointed 
•out that in the trunk characters, especially the thoracic, these insects were fundamentally much 
less allied to the Lepidoptera than has been supposed. 
But in the mouth parts also we have a character of fundameutal importance which still further 
separates the two orders, notwithstauding the fact that both orders in the imago state lack 
maudibles. This is the presence in the maxilla of Eriocephala of a lacinia, and of a true galea, 
while the maxilla of Trichoptera entirely differs, having not only no lacinia, but a much reduced, 
almost vestigial, galea, ^ the maxillary palpi being very large. 
In respect, then, to the maxill®, the Lepidoptera are nearer the ametabolous, mandibulate 
insects than the Trichoptera, while some genera of the former order (Eriocephala) have well- 
formed mandibles, and many others (Tineid®, Pyralid®, and Crambid®) have vestigial ones. 
In fact the venation of Eriocephala and of Micropteryx is in general remarkably like that of 
Amiihientomum, a generalized Psocid, and it is not altogether imx)Ossible that these insects 
with their reduced prothorax and concentrated or fused meso and metaihorax, together with their 
maxillary fork, may have liad some extinct allies which were related to the remote ametabolous 
ancestors of the Lepidoptera. 
Here might be recalled the suggestion of Hermann MiiUer in the same address from which we 
have just quoted, that there is a close relationship between the Tipulari® and the Lepidoptera, in 
the similar venation of the wings in many Tii)ulari® (Limnobia, Cteuopliora) and the Phryganeid®, 
“and, finally, the circumstance that it is far easier to deduce morphologically the proboscis of the 
Tipul® from the buccal organs of the Phryganeid® than from those of any other order of insects.” 
By this statemeiit he i^rohably means tlie strong resemblance of the haustellum (rather a lapi>ing 
organ than a sucker) of the Trichoptera to the lapping organ or proboscis of the Dii)tera. This is 
-a i)oiut which needs further examiuatiou. The close similarity of the pupa of the more generalized 
Diptera and of the more generalized Lepidoptera also needs to be emphasized, for it is suggestive 
of an early close relationship between the two orders, 
^Eut. Zeitung, Stettin, Jalirg. 31, p. 202, 1870. 
2 The cases of a trichojiterous insect have recently been discovered by Dr. Anton Fritsch in the Permian beds of 
Bohemia. K. hdhm. Gesellschaft der AVisaenschafteu, November 23, 1894. The earliest Lepidopterous remains, 
referred to a sphinx and to Pterophorns, occur in Jurassic strata. 
®See our figure of the maxilla of Limnephilus, fig. 4, PI. LIX {lac should be galea), Third Report United States 
Entomological Commission. 1883; also the much more detailed figures of R. Lucas in his Beitriige zur Kenntniss der 
Mundwerkzeuge der Trichoptera, 1893. 
