142 DR. E. KLEIN AND PROFESSOR BURDON SANDERSON. 



depend on the form of the insect when hatched, and its mode 

 of life. 



The leptiform larvae of insects may be compared with the 

 nauplius form of Crustacea, and in a much less degree the 

 eruciform to the zoea form. The three higher suborders of 

 insects may be compared to the Malacostraca with their zoea3- 

 forni larvse, and the four lower suborders (Coleoptera, Hemi- 

 ptera, Orthoptera and Neuroptera) with the Entomostraca/ 

 in which certain forms, as some Phyllopods, and Limulus, 

 and the Trilobites, are hatched in a subzoea condition (corre- 

 sponding to the eruciform larvee among the Neuroptera and 

 Coleoptera). The larvae of the earliest insects were pro- 

 bably leptiform, and the eruciform condition is consequently 

 an acquired one, as suggested by Fritz Miiller.^ His sugges- 

 tion, followed up by Brauer, that the insects have descended 

 from some zoea does not seem of much value, as the leptiform 

 larva more exactly parallels the nauplius of the lowest Ento- 

 mostraca (Copepoda). We have already suggested that the 

 Insects and Crustacea probably arose by two distinct lines of 

 development from the worms, rather than that the Nauplius 

 gave rise to the Insects, as Miiller has suggested ; an impor- 

 tant reason for this view being that the three pairs of appen- 

 dages of the Nauplius do not homologise with the distinct 

 cephalic and three thoracic appendages of the Leptus. 



Preliminary Notice of Researches on the Anatomy of 

 the Serous Membranes in Normal and Pathological 

 Conditions. By Dr. E. Klein awe? Professor Burdon 

 Sanderson.^ 



Being engaged in the study of secondary inflammations, 

 we propose in the following pages to give briefly the results 

 from an anatomical point of view, to which our investiga- 

 tions have led us. These communications relate, however, 



^ The terms Malacostraca and Entomostraca are used for convenience 

 not that they are entirely natural divisions. 



- " It is my opinion that the ' incomplete metamorphosis ' of the Ortho- 

 ptera is the primitive one, inherited from the original parents of all insects, 

 and the ' complete metamorphosis ' of the Coleoptera, Diptera, &c., a subse- 

 quently acquired cue." — Fur Darwin, Eiig. Trans., p. 121. 



^ Forming a part of investigations on infectious diseases, undertaken for 

 the Medical Department of the Privy Council. — From ' Ceutralblatt fiir 

 Med. Wiss.,' 1872, Nos. 2, 3, 4. 



