M' 1 1 INC. — NKMA'IOCYSTS. 



NEMATOCYSTS. 



HN I'ROI'. t . C. NL "I'lINC, M. S. 



Ao.s/ra,t; 



N(Mnat(>;-\ sts or ciiidocclls or ".stinniiiu- cells"" :i> they \\\\\v 

 Ih'cii \ :iri()usl\- called, are fomul in many ( '(nloiftn-afcs and 

 some Pld iKirid IIS. 



Three types occur in J Ii/(1y(i\ \\\\\\\v\x : First, small i)ear- 

 ^haped : second, small oval with l()ii<; thread; tliird, flask- 

 shaped \vit!i harhs, the latter oceiirin<>- also in JMfUtqxn'd and 

 known as the Injilnnd type. 



In Piii/siiJtd drefhiisd they are found in head-like purple 

 hodies which are arranii-ed alo'.iof the locomotor tentaclos and 

 curled around them when retracted. These tentacles ai'e 

 homoloii-ous with t lie '' tii-htinii' JL/(/r(c" of JIi/(lroiiir(/>is(('. 

 The ncmatocysts are loimd, purple and i)r()ject a crimped 

 tliread. 



\'ery complicated ncmatocysts o;-cur in certain corals, udta- 

 l)ly /sdj//i////id t/qisdcid where they are found jiacked aloni;- oni^ 

 side of tentacles which [)rotrude from the mouth of the coral. 

 These laru'e and complicated ncmatocysts were doscrihed and 

 experiments and ohscrxat ioirs reirai'diii'jf them related. 



The use of these cells was discussed, and the testimony of 

 Agassi/, Dana, Tarr and (iosse to the fact that thcthi-ead 

 penetrated the suhstances attacked, was o:iven. 



The testimony of Lewes and observations of tlie author were 

 i^iven in op[)osition to the views of those who upheld that 

 l)enet ration was necessary to efl'eetive use of iieniatoeysts. 

 The author stated that the neniatoeysts of Phifsah'(f eovdd net 

 oi- at least produce irritation lonir after tliey had heen eoni- 

 pletely di-ied and presumably incapable of projectinir their 

 threads. 



[I>R.K. 1. A. S.. iSS;- .] 95 |M.irch lo. 1889.) 



