and Laboratory Methods. 1211 



segment shows it to be a primary head segment. The mandibles develop from 

 simple papillae, and are only lobed in Campodea ; they are homologous with the 

 mandibles of Pter)-gota, Scolopendrella, Crustacea, and probably Diplopoda and 

 Chilopoda. The hypopharynx consists of two dorsal " superlinguae," develop- 

 ing from a pair of papillae between the mandibular and first maxillary segments, 

 also a ventral lingua. First maxillae develop as in Orthoptera. A palpus 

 appears in the embryo, which disappears before hatching. The labrum of 

 Anurida develops from a pair of papillae from which the entire gular region is 

 derived. A palpus appears, but is resolved. It is homologous with the Pterygota 

 structure, agrees in detail with the first maxillipeds of decapod Crustacea. The 

 sides of the face develope from a lateral evagination near the mandibular seg- 

 ment, which eventually involve the labral and labial fundaments. These folds 

 are of Collembola, Campodea, and Japj'x, are homologous with the genae of 

 Pterygota. The dorsal region of the skull in Anurida does not differentiate 

 into sclerites comparable with those of the Pterygota. The evidence is for seven 

 segments in the head, as is probably true for all Hexapods. Ocular, antennal, 

 intercalary, mandibular, superlingual, maxillary, labial, with ganglia, and a pair 

 of appendages for each. The Collembola resemble Campodea and Japyx in 

 structure, their entognathous characteristics separating these groups from the 

 rest of these insects. The Collembola are somewhat more specialized than the 

 Thysanura in general structure. The Aphoruridae, including Anurida, are the 

 more generalized and probably degenerate forms. The resemblance in most 

 parts indicates that the primitive collembolan descended from the stem form of 

 Campodea, the affinities of Campodea, and in two directions, towards Machilis and 

 Lepisma, and towards Scolopendrella. a. m. c. 



Kizer, E. J. Formalin as a Reagent in Blood This has been found a useful reagent 

 Studies Proceed. Indiana Acad, of Sci., p. j^ bringing out blood Structures. It 



222-2, 1898. . . 



produces no visible distortion, does not 

 interfere with staining, and is an excellent preservative. One volume of fresh 

 blood is mixed with three volumes of two per cent, formalin, and after standing 

 for an hour a drop is pipetted from the sediment to a cover slip, and allowed to 

 dry by evaporation after being spread evenly. Slips are fixed in a flame, and 

 dipped once or twice in a five per cent, solution of acetic acid. The acid is 

 removed by water, and two per cent, gentian-violet is used, or methyl-blue and 

 gentian-violet, or haematoxylin and eosin, methyl-green and safranin, or Ehrlich's 

 triple stain. Excess of stain is removed by water or alcohol, as the fluid requires. 

 Mounted in balsam. a. m. c. 



Baum, J. Beitrage zur Kenntniss der Muskel- The author used the muscles of man 



spindeln. Anat. Hefte. H. 42, 43. 249-306, ^nd Other mammals (especially the 

 4 Tafler, 1900. ^ ^ ^ 



hedgehog, guinea pig, dog, cat, rabbit 



sheep, pig, mole) also of Pristiurus melanostomus, Syngtiathus phlegon, Petro- 

 myzon, and the frog. The muscle was studied fresh; it was isolated in con- 

 centrated caustic potash, which does not affect the nuclei an-d fibres, but loosens 

 the connective tissue, so that in fifteen minutes separation is easy, but great 

 pressure on the cover-glass must be avoided. Acetic acid is used for isolation 



