PHRAGMICOMA. 



[ 594 ] 



PHTHIRITJS. 



glasses a lens of 5" focus ; for the 1" a lens 

 of 8" focus. 



Microscopic photographs are best obtained 

 with solar light ; but artificial light has been 

 used, as that from camphene or gas for low 

 powers, the oxyhydrogen light for high 

 powers, andMaddox has used the magnesium 

 light. A great point is to secure clean pre- 

 parations, with the object sufficiently flat to 

 allow of being clearly focused all over ; this 

 sets a limit to the utility of the process ; 

 further, certain objects in which red and 

 yellow, or yellowish-brown colours exist, do 

 not transmit the light, or only imperfectly. 

 It will probably be advantageous to bleach 

 many objects, as, for instance, insects and 

 their parts, by long maceration in turpen- 

 tine, sections of dark-coloured wood by 

 nitric acid, &c., when they are intended to 

 be photographed. 



The purely photographic manipulation 

 cannot be given here, but requires the ordi- 

 nary skill in photography. Lengthened 

 particulars respecting the application of 

 photography to the microscope are contained 

 in the papers referred to below. 



BIBL. Highley, Qu. Mic. Jn. i. 178, 305, 

 and ii. 158 ; Shadbolt, Qu. Mic. Jn. ii. 165; 

 Wenham, Mic. Tr. 1855, 2. iii. 1 ; Rood, 

 Qu. Mic. Jn. 1862, 261 ; Hessling and Koll- 

 mann, Atlas, d. thier. Geweb. 1862 ; Maddox, 

 Tr. Mic. Soc. 1863, 9 ; ibid. 1865, 34 ; Jn. 

 Lond. Photo. Soc. 1864 ; Mn. Mic. Jn. 1869, 

 27 ; Woodward, ibid. 29, vol. iii. 290; Qii. 

 Mic. Jn. 1870, 380 ; Brit. Jn. Photo. 1866 ; 

 Moitessier, Photog. Appliquee, 1866; Reich- 

 ardt and Sturenburg, 1868, Mon.mik. Phot.; 

 Benecke, Photogr. 1869 ; Hermann, Phot. ; 

 Gayer, Micro-photogr. ; M. M. Jn. xv. 258 ; 

 Frey, Das Mik. ; Beale, How $c., and the 

 notices therein. 



PHRAGMIC'OMA, Dumort. A genus 

 of Jungermannieae (Hepaticae), containing 

 one British species, P. Mackaii (Jung. 

 Mackaii, Hook.), occurring 

 rarely on trees and rocks, espe- 

 cially on limestone. 



BIBL. Hook. Br. Jung. 63 ; 

 Ekart, Syn. Jung. 59, pi. 9. 

 fig. 72 ; Endlicher, Gen. Plant. 

 Suppl. i. 472-9. 



PHRAGMIDTUM, Lk. 

 (Aregma, Fr.). A genus of 

 Uredinei (Ooniomycetous 

 Fungi), forming rusts very i 80 iated basi- 

 common on Rosaceous plants. <*ium with four 

 *ey appear upon living jgfcJBSL 

 leaves, breaking through from 



Fig. 565. 



Phragmidium 

 bulbosum. 



beneath the epidermis, and are chiefly dis- 

 tinguished from PUCCINIA by the number 

 of septa which are contained in the spores 

 or pseudospores. P. bulbosum is common, 

 forming yellow and brown pulverulent 

 spots on bramble-leaves (see AREGMA). 



BIBL. Berk. (Areffma), JBr. Fl. ii. pt. 2. 

 358 ; Grev. Sc. Crypt. Flor. pi. 15 ; Tulasne, 

 Ann. Sc. Nat. 4 s5r. ii. 180, pi. 9 ; De Bary, 

 Brandpilze, 1853, 49, pi. 4 ; Fries, Sum. Veg. 

 507 ; Currey, Q. J. Micr. Sc. v. 117. 



PHRAGMOTRICH A 'CE^E. A family 

 of Coniomycetes, distinguished from Melan- 

 coniei by their moniliform chains of spores. 

 See CONIOMYCETES. 



PHRAGMOT'RICHUM, Kze. A genus 



Fig. 566. 



i 



Fig. 567. 



Fig. 568. 



Phragmotrichum Chailletii. 



Fig. 566. Scale of a spruce-fir cone, with pustules. 



Half nat. size. 



Fig. 567. A pustule, magnified ]0 diameters. 

 Fig. 568. Vertical section across a pustule, showing 



the chains of spores. Magnified 100 di 



of Phragmotrichacese (Stylosporous Fungi). 

 The plants form little tubercles bin-sling 

 out from beneath the epidermis, and con- 

 taining filaments arising from a softish 

 fibrous stroma. The filaments (basidia) 

 are interrupted at intervals with cellular 

 spores (fig. 568), which ultimately separate. 

 P. Chailletii grows upon the scales of the 

 cones of Abies exceha. Other species grow 

 on the poplar and maple. 



BIBL. Fries, Syst. Myc. iii. 492; Sum. 

 Veg. 474 ; Berk. Crypt. Sot. 327. 



PHTHIR'IUS, Leach. A genus of 

 Anoplura, family Pediculidae. 



Char. Legs of two kinds, anterior pair 

 formed for walking, posterior pairs for 

 climbing ; thorax large, not distinctly sepa- 

 rated from the abdomen. 



