r>>-,tj ibur on : Endemic in the Brisbane Ranges. Victoria, and then uopur- 

 jSnrty guile plentiful over a coiviidcrabli. area, ill the generis I vicinity oi ihe 

 U>\\t)$hip ol Steiglil/ 



U, ttfiyltlsiatia also has been included, tt. file pa,sj with {7. i/nfte/m, bv.l 

 differs in lea* shape, and 111 the type ol venture on the leave.-:. on the peiinmb 

 jVkI jgfl the ovary ftnd base of ffw <Hyl£, It bearc & nmTirkaSIc, ^iperficul 

 resembUutce lo (7. <{rvof>h)ifa t diJTerin^ numly in the lyptf of vestiture on 

 tltt* lemrs in ilte si/-: ql tic floats. Ill the uipi-aie ovary ami •lie sotncwlMt 

 o-ilKSretil siyle 



L wisii to thanV* the Director enfl stafl 6* the Melbourne National 

 Herbarium for facilities in coimrrliPn with this mcarr'v 



ON CH005ING A MICROSCOPE FOR THE NATURALIST 



By C S. Mi pro*— ox, f.r.a.s.j r.n.M.s. 



Oue is frequently asked lot atlvi.ee on Lite choice of a microscope foi a 

 particular purpose. Here- I shall ir>' to answer the Naturalist. 



A*- microscopes are designed to fill speciric net*ds in spex lalized fields, a 

 very good (or expensive) microscope may not be the most suitable, 



Microscopes to-day arc chiefly designed for : ( 1 ! Medical s?uricm* * 

 (?) MeuidniyiiU : (3) (jcologists ; ami (4) J.ar^e J-aboratoHes, when' 

 torae universal instruments sometimes routine iJ.OljO or mote an? pfuwdra 

 The Naturalist appears to have been foryotteu in these days, especially dhc 

 mari with not loo deep u pocket. 



The so-called single purpose research microscopes for hiok-fjeal work are 

 generally Jink- more thin ;t ntedieaJ .student's microAiope, with a mechanics) 

 stage and perhaps a ic.ck-iocusMng iub*slae,t. Such a:i instrument, with lh~ee 

 objectives, viz, lOx, 4Dx. and IllOv oil immersion, .mil two eye-pin «*£ — $s" **od 

 K)x, sells to-day for ahnJt il50 and is nut suitable for ihe NaUirali^T He 

 requires a greater range or low powers than this, and the IOOx oi; imnier&icn 

 objective is seldom, if ever, required. 



How then Can he ehot>se wisely and wcJl f " What s ha old lie look f or ■ 



There are four main features : ii) Objectives i <u) Tye pieces; (ui'i J>tih- 

 sta^e condenser ; (iv) Stand. 



{i) Objectives: The lull battery oi objectives best suited to the tiatUi aliSi 

 would be a J inch, 2 inch, I inch, 8 mm. and a 3 mm, dry achromatic, not 

 apocriromatie. 



While not decrying the apnrliroma'.ic ohjt-ctive tor cerUin cntieal WQfk hy 

 an experienced nn<;n>fcopi^t, these bcauiiful and very expensive le'ise* Jirp 

 liy no nieaiis siniahte for rhe average naturalist as. unless critically used, tIicv 

 may yield poorer images than an achroinat of aimilar ixiwer, '1'he apuchroniat 

 is much more sensitive to variation tn tube length and eover-gLiss thicfcue-Sa 

 and also has a ni-jrc curved field- These arc disadvantages under ucrtam 

 Lircumstaiiceb. The expense of apochronuU i-5 only wartanted where the 

 titmnst resolution is necessary for the work in hand and in critical photo- 

 rnicftyraphy. 



The purchase, of aU these lenses- may be too •expensive at nr.5t. If so. 

 purchase the 2 inch and S mm., and add the rest as necessary. 



(u) Eyepieces: (jet o-rie eyepiece as hiyh a power as possible, preferably 

 an ouhoscopic. and an 3>. huy^nian. 



(iii) Huh-_ma£je Condenser: The best \% n do achtomatir and aplastic 

 condenser. 



An aplanalie condenser, not corrected for colour, is also very suitable it' 

 utcd with tiLtcrs. Tliesc arc hoth Tather cvpen>i\e but may sometime- he 

 houftht secondhand Failing that, then buy an Abhe remdenser, preferahh - 

 a 3 leu* form. 



