ACTINOPTYCHUS. 



ADULTERATIONS. 



deeper and deeper, in which the organism is 

 finally lodged. As the depression becomes 

 still deeper, its edges coalesce, and thus a 

 cavity closed on all sides is formed, in which 

 it remains for a certain time and becomes 

 digested. If there be any indigestible resi- 

 due, a passage for its exit is formed, and it 

 is expelled by further contractions of the 

 substance of the body, and in the same or a 

 different direction from that at which it en- 

 tered, the canal and the aperture entirely 

 disappearing. M. Kolliker also noticed the 

 remarkable fact, that two perfectly distinct 

 individuals became gradually fused so as to 

 form a large single animal. The results of 

 this conjugation were not traced. 



BIBL. Kolliker, Zeitschr. f. Wissensch. 

 Zoologie, Bd. i. (Qt. Journ. of Micr. Science, 

 vol. i.) ; Stein, Archiv. f. Naturgeschichte, 

 1849; Brightwell, Fauna Infusoria of Nor- 

 folk ; Pritchard, Inf. Animate . 



ACTINOPTYCHUS, Ehr. A genus of 

 Diatomaceae. 



Char. Frustules solitary, free, disk-shaped, 

 with rays and internal radiating septa ; valves 

 apparently cellular (areolar), except opposite 

 the rays. 



Kiitzing enumerates 16 species, distin- 

 guished principally by the number of septa 

 and rays: A. ternarius, septa 3; A. quater- 

 narius, septa 4; A. senarius, rays 6 (PI. 

 18. fig. 45), &c. Another species, A. hex- 

 apterus, has 6 thick, solid conical rays ; the 

 margin of the disc thick, undulate, and 

 toothed within. Many of the species are fos- 

 sil, none British. 



ACTINOTHYRIUM, Kunze. A genus 

 of Sphaeronemei (Coniomycetous Fungi), 

 forming minute, round, p- 3 



flat, black spots, with a 

 central boss of close, 

 radiating, fibrous struc- 

 ture. British species : 



A. graminis, Kunze. 

 On leaves and stalks of 



Grasses in Spring (fig. Actinothyriuin graminis 

 3). (highly magnified). 



The innate, radiately fibrous, shield-like 

 perithecium finally dissolves at the apex. 

 The spores, which are spindle-shaped, are 

 formed beneath the disk ; their development 

 and mode of attachment do not seem to 

 have been made out. 



BIBL. Greville, Scott. Crypt. Flora, t.218. 



ACTINURUS. A genus of Rotatoria, of 

 the family Philodinsea, Ehr. 



Char. Eye-spots two, frontal (red) ; tail- 

 like foot with 2 lateral horny processes and 



3 terminal toes. (Rotifer with 5 points to 

 the foot.) 



Agrees with Rotifer in general structure ; 

 teeth 2 in each jaw (PI. 34. fig. 2). 



1 species, A. Neptunius (PI. 34. fig. 1). 

 Colourless, body attenuated ; length 1-18 to 

 1-36". Very common, aquatic. 



ADIANTUM, Linn. A genus of Asple- 

 nieae (Polypodaeous Ferns), with one elegant 

 indigenous, and many exotic species. 



Fig. 4. 



Adiantum (pinnule with sori covered by indusia) : 5 diam. 



ADULTERATIONS. A very important 

 use to which the microscope is applicable, 

 consists in the detection of various adultera- 

 tions of articles of food, drugs, and products 

 of the arts and manufactures. We have no 

 space here to enter into the details of this 

 question as regards the individual substances 

 liable to be adulterated, or used as adulte- 

 rating ingredients, but must confine our- 

 selves to a few general remarks. Further 

 particulars will be found under the special 

 heads of articles of food, &c., such as 

 COFFEE, TEA, STARCH, &c. 



The first point in a question of adultera- 

 tion, is to determine, by microscopic and 

 micro-chemical analysis, the structure and 

 composition of the pure substance; and if 

 the Table given at pajge xl of the Introduc- 

 tion be kept in view in this proceeding, but 

 few points will probably be overlooked. On 

 then comparing these results with those ob- 

 tained by a similar mode of proceeding in 

 regard to a suspected substance, there will 

 in general be found little difficulty in deter- 

 mining 'whether it be pure or not. If im- 

 purities or adulterating ingredients are pre- 

 sent, the next point will be to determine 

 their nature. To do this with certainty, 

 would require that the structure and compo- 



