October 1, 1887.] 



♦ KNOWLEDGE ♦ 



267 



PLEASANT HOURS WITH THE MICROSCOPE. 



By Hexry .J. Slack, F.G.S., F.R.M.S. 



E\V phenomena in nature excite more as- 

 tomshmentthan tliegi^at changes in form, 

 habits, and capacities -svhich many crea- 

 tures visibly undergo in their passage 

 from an infantile to an adult state. The 

 transformations of insects must have been 

 the firet to attract attention, unless per- 



mav hav^ h.. ^P' '','''*""'' °^ *'^® ^'''Jpole *« t^e frog 

 may liave been recognised at a still earlier timp Tht 



Sn'^r -"f ""T *'>^"- t-nsformatTon butdo lo 

 begin an independent existence until thp^ o^^ • 



mate,, fi,i3hed No one cou'" heStlt rro-^t^": 

 kitten as a small c^t, or a puppy as a little dog buf^iSout 

 actually seeing it come to pass" no one would^imalile that 

 a caterpillar was an incipient butterfly or iT,Hno]» 

 incinienf frr.rr \,~ 1 """^"^'"^j or a tiidpole an 



incipient trog. As more and more is known of the wavs of 

 nature m the organic world, greater numbers of InTtances 

 are noted m which early life stages are passed under such 

 differences of aspect and org^xnisation as to throw into con 

 tT . ■n''^'''"? ^^^^'""^ ^f individualism and specTes" 



ttreef t7w:'' 'f^'^^'' '^"^ "^""^^ °- individuTor 

 three? If we make a jump from the lower forms of life 

 o man, we might consider continuation of self-co^cioIneS 

 as sufficient evidence that child, youth, and mrwe^o^ 

 happens tW P^-^^f ^7- but,how when, as occasionaHy 

 happen.-, there is a breach in the continuity, the same 

 man or woman exists in two or more distinct lives T^h 

 having peculiar and separate ideas, recollections, tho^Xs 



iTknnw 't '''"?''*''' ^ ^^' "^'^^ --^ «tudy the Ks^ 

 liie known to us, it seems that a man can be somebody eke 

 besides himself, we may the less wonder that rSmptr 

 alTmay'ir' ^PP^^^^ complete, distinct ISt 

 creature ^ successively belong to one and the same 



to^L'^'^^ff* "" 'P^'^f ^* "^'^^^ t° be thought sufficient 

 to .how that a particular form, structure, aSd cWcter 

 were transmitted with considerable accuracyTnd pre^bn 

 through many generations, but in recent timasTv^^ 



Sr^and th:lT%'="^ ^T ^'^'^'^^-^^ i" "hi^h X 

 different slm. 1^'.. ™' °^ *^' """^^ ''^'"^^ ''^^ widely 

 fUTt a' °V'''' """"^ remarkable cases have been 



detected amongst the infusoria through the researches of 

 Drs. Dalling. r and Drysdale. In one set of their verv remark 

 able investigations they found that after keepin/kmaTra 

 tion of cod's head for two or thi-ee months, vast numbed of 

 a certain monad appeared as little egg-shaped bodTraboi t 

 IT;^ K ^^'^V/"'"' ^'"^ provided with two Ion- very 



ven 'the Ind T """"''f'"" "^P''^'-^ ^^i' -If-division^ 



alcordii" ti i T P' 'P''"'°» '"^ ^"°- Here then 

 according to old notions, was a good sneeies hut h^- ;„„„ 



sant watching from hour to hour an^ k to "Ura 

 small triangular cre^iture, swimming with four whips 



thetil- °°' ^"""i '""'^''"'^ '^f -y connect on wi^h 

 the precedmg animals, was found to be related to them 

 m a most curious way. In the same field were som^ 

 minute globes, showing nuclei, and gently wavin<. a couSe 

 of whips, between which, after a period of qu^esoencL a 

 small cone of sarcode was pushed out, and p^oIonleHnto 

 f}.. h fy^''''^"^'- P'-°'^e«es this whip diWded into two 

 the globe became oval and then spHt in two. The a-eatuTe^ 

 thus formed each joined one of the first^mentioned 7m 

 their bodies united and grew into a triangular object wUh 

 two pairs of whips. After a time the whips dSpLred 

 and the object looked structureless and dLd T^n an 

 internal commotion ensued, and finaUy the thing burst and 



otnew fet™n: «' ^'^ "''^"*'^* ''"^ ^^'^^- '^^ »--^ 



to^the°Dai-w;°^ '^'lu'"'^ "°* °"^-" ^^' ^-^ ■■'^-^1"-We help 



micitcoSsts to he '"'■•'' '"* P'-^P'*'-^'^ '-'" t'^°"g''tf"l 



SJectrtr/eprlent '^ ^^^''T " """"'"" '^"-"=^1 

 if \„ "represent in an fxclusive way anvthinw thit 



to Tali a "*'"■ P'^"-°P'»->- or pro/isionally L d 



tra""o:t;P"'"' "°'"" '*^ ^"^"-^ "f-^-t-y had beei 



<n;atwmro7thJw- ^""'^ Kent, and described in his 



Sterestin" ff ' ^?"°'^, *^=^* * well-known and highly 



mteresting infusoria, the Actlnophr,,s Sol was the fin,l 



other foLfrh'S"^' ''"'' Y^^^^on4 exLteS L 'wo 

 from the Lfs? "'n^ V^'^y ^'^^ the other, and also 

 irom the last stage. Copying Jlr. Kent's ti-ures we find 

 1) a pear-shaped bag, full of fine granule7with Il-n-.e 

 round vacuole near the thickest end? and a dXate whfp 

 springing from the thin one. This is not at all L ,,1^ 



StowtuVirJikl'T i nothing in r JptaWt^o 

 inoicate what it is hkely to do, or how to distinguish it with 

 any certai-.ty from similar monads which will "not undlrlo 



spec s"' ittofT- f ^""^ "T'^ ^^^"^ l-"^- like a dS 

 species. -Instead of a smooth pear-shaped bod^■, we see one 



taTntl^t. '' °7m "'*' l--ge conical projecti;ns bi't 1^! 



w have a'ddl'^t 1 T^^'N" °'"=^" A4//«m). FinaHy 

 we have a deliaite globe, with a vacuole, a nucleus and an 

 aureole of extremely fine rays .springing from the 'intemd 



Fig. 1. 



S^^^J:'-'-'- 



:::-^-0f^f^:::- 



Fig. 3. 



Fig. 2. 



sarcode mass. The pear-shaped form not only differ 



Tor ^f 'r/PP'r'^'^" ^•■°'^ *'>^ actinophrys form ^but th^ 

 mode of hfe and organisation is changed.^ The fiist ha^\ 



S Thetf'*/'''^ '"^^ '""^ "' -" swim afteild 

 catch. The actinophrys waits till some appropriate object 

 happens to touch one or more of its i-ays, when ?K seize i 



:^:^"it^S:- vrtcsi, ^,^±t 



:^-Xl° trT '/t'=""S P°"---- If t^ey were m'erTv like 

 sticky threads of glue, the whole creature would soon b^ 



flagdk. °' ^^ '^^ •"«^«'"ents of their cilia or 



In the pear-shaped form we recognise nothing to remind 

 us of the amceba, but the delicate rays of safcode'n he 

 actinophrys form suggest relationship L variou groups of 

 creatures, with or without shells, who obtain theS by 

 extending pseudopodia of sarcode, which, whether thicker 

 :2edr;r""' "P'-^P^^"- '^^ prolongations'otth: 

 _±^^2^^f^^^^o[^^^ked^ctino ^js (fig. 4) was found b y 

 » See Mont/ily Microscopical Journal for 1873. 



