Tim spotted two more animals； on higher branches of the same tree。 They were all about the same size。 None of them were moving。
〃Pretty boring；〃 Lex said。 〃They're not doing anything。〃
〃The main herd of animals can be found in the grassy plain below you；〃 said the voice。 〃We can rouse them with a simple mating call。〃 A loudspeaker by the fence gave a long nasal call； like the honking of geese。
From the field of grass directly to their left； six lizard heads poked up； one after another。 The effect was ical； and Tim laughed。
The heads disappeared。 The loudspeaker gave the call again； and once again the heads poked up…in exactly the same way； one after another。 The fixed repetition of the behavior was striking。
〃Hypsilophodonts are not especially bright animals；〃 the voice explained。 〃They have roughly the intelligence of a domestic cow。〃
The heads were dull green； with a mottling of dark browns and blacks that extended down the slender necks。 Judging from the size of the heads； Tim guessed their bodies were four feet long； about as large as deer。
Some of the hypsilophodonts were chewing； the jaws working。 One reached up and scratched its head； with a five…fingered band。 The gesture gave the creature a pensive； thoughtful quality。
〃If you see them scratching； that is because they have skin problems。 The veterinary scientists here at Jurassic Park think it may be a fungus； or an allergy。 But they're not sure yet。 After all； these are the first dinosaurs in history ever to be studied alive。〃
The electric motor of the car started； and there was a grinding of gears。 At the unexpected sound； the herd of hypsilophodonts suddenly leapt into the air and bounded above the grass like kangaroos； showing their full bodies with massive hind limbs and long tails in the afternoon sunlight。 In a few leaps； they were gone。
〃Now that we've had a look at these fascinating herbivores； we will go on to some dinosaurs that are a little larger。 Quite a bit larger； in fact。〃
The Land Cruisers continued onward； moving south through Jurassic Park。
Control
〃Gears are grinding；〃 John Arnold said； in the darkened control room。 〃Have maintenance check the electric clutches on vehicles BB4 and BB5 when they e back。〃
〃Yes； Mr。 Arnold；〃 replied the voice on the inter。
〃A minor detail；〃 Hammond said； walking in the room。 Looking out； he could see the two Land Cruisers moving south through the park。 Muldoon stood in the corner； silently watching。
Arnold pushed his chair back from the central console at the control panel。 〃There are no minor details； Mr。 Hammond；〃 he said； and he lit another cigarette。 Nervous at most times； Arnold was especially edgy now。 He was only too aware that this was the first time visitors had actually toured the park。 In fact； Arnold's team didn't often go into the park。 Harding； the vet； sometimes did。 The animal handlers went to the individual feeding houses。 But otherwise they watched the park from the control room。 And now； with visitors out there； he worried about a hundred details。
John Arnold was a systems engineer who had worked on the Polaris submarine missile in the late 1960s； until he had his first child and the prospect of making weapons became too distasteful。 Meanwhile； Disney had started to create amusement park rides of great technological sophistication； and they employed a lot of aerospace people。 Arnold helped build Disney World in Orlando； and had gone on to implement major Parks at Magic Mountain in California； Old Country in Virginia； and Astroworld in Houston。
His continuous employment at parks had eventually given him a somewhat skewed view of reality。 Arnold contended； only half jokingly； that the entire world was increasingly described by the metaphor of the theme park。 〃Paris is a theme park；〃 he once announced； after a vacation； 〃although it's too expensive； and the park employees are unpleasant and sullen。〃
For the past two years； Arnold's job had been to get Jurassic Park up and running。 As an engineer； he was accustomed to long time schedules…he often referred to 〃the September opening；〃 by which he meant September of the following year…and as the September opening approached； he was unhappy with the progress that had been made。 He knew from experience that it sometimes took years to work the bugs out of a single park ride…let alone get a whole park running properly。
〃You're just a worrier；〃 Hammond said。
〃I don't think so；〃 Arnold said。 〃You've got to realize that； from an engineering standpoint； Jurassic Park is by far the most ambitious theme park in history。 Visitors will never think about it； but I do。〃
He ticked the points off on his fingers。
〃First； Jurassic Park has all the problems of any amusement park…ride maintenance； queue control； transportation； food handling； living acmodations； trash disposal； security。
〃Second； we have all the problems of a major zoo…care of the animals； health and welfare； feeding and cleanliness； protection from insects； pests； allergies； and illnesses… maintenance of barriers； and all the rest。
〃And； finally； we have the unprecedented problems of caring for a population of animals that no one has ever tried to maintain before。〃
〃Oh； it's not as bad as all that；〃 Hammond said。
〃Yes； it is。 You're just not here to see it；〃 Arnold said。 〃The tyrannosaurs drink the lagoon water and sometimes get sick； we aren't sure why。 The triceratops females kill each other in fights for dominance and have to be separated into groups smaller than six。 We don't know why。 The stegosaurs frequently get blisters on their tongues and diarrhea； for reasons no one yet understands； even though we've lost two。 Hypsilophodonts get skin rashes。 And the veloctraptors…〃
〃Let's not start on the velociraptors；〃 Hammond said。 〃I'm sick of hearing about the velociraptors。 How they're the most vicious creatures anyone has ever seen。〃
〃They are；〃 Muldoon said； in a low voice。 〃They should all be destroyed。〃
〃You wanted to fit them with radio collars；〃 Hammond said。 〃And I agreed。〃
〃Yes。 And they promptly chewed the collars off。 But even if the raptors never get free；〃 Arnold said； 〃I think we have to accept that Jurassic Park is inherently hazardous。〃
〃Oh balls； 〃 Hammond said。 〃Whose side are you on； anyway？
〃We now have fifteen species of extinct animals； and most of them are dangerous；〃 Arnold said。 〃We've been forced to delay the jungle River Ride because of the dilophosaurs； and the Pteratops Lodge in the aviary； because the pterodactyls are so unpredictable。 These aren't engineering delays； Mr。 Hammond。 They're problems with control of the animals。〃
〃You've had plenty of engineering delays；〃 Hammond said。 〃Don't blame it on the animals。〃
〃Yes； we have。 In fact； it's all we could do to get the main attraction； Park Drive； working correctly； to get the CD…ROMs inside the cars to be controlled by the motion sensors。 It's taken weeks of adjustment to get that working properly…and now the electric gearshifts on the cars are acting up！ The gearshifts！〃
〃Let's keep it in perspective；〃 Hammond said。 〃You get the engineering correct and the animals will fall into place。 After all； they're trainable。〃
From the beginning； this had been one of the core beliefs of the planners。 The animals； however exotic； would fundamentally behave like animals in zoos anywhere。 They would learn the regularities of their care； and they would respond。
〃Meanwhile； how's the puter？〃 Hammond said。 He glanced at Dennis Nedry； who was working at a terminal in the corner of the room。 〃This damn puter has always been a headache。〃
〃We're getting there；〃 Nedry said。
〃If you had done it right in the first place；〃 Hammond began； but Arnold put a restraining band on his arm。 Arnold knew there was no point in antagonizing Nedry while he was working。
〃It's a large system；〃 Arnold said。 〃There are bound to be glitches。〃
In fact； the bug list now ran to more than 130 items； and included many odd aspects。 For example：
The animal…feeding program reset itself every twelve hours； not every twenty…four hours； and would not record feedings on Sund